diff --git a/CHANGES b/CHANGES
index 5ed5e6e..96d4652 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,34 @@
-The following are the changes from calc version 2.12.5.0 to date:
+The following are the changes from calc version 2.12.5.1 to date:
+
+    Removed rules and makefile variables assocated with shortened
+    calc version numbers of less than 4 levels.
+
+    Under OS X (darwin), if /usr/include is missing, warnings
+    are issued to help the user use xcode-select --install
+    so that one may properly compile C code.
+
+    Lowered REDC levels:
+
+	#define MAXREDC 256	/* number of entries in REDC cache */
+
+	#define SQ_ALG2 28	/* size for alternative squaring */
+	    config("sq2") == 28		/* was 3388 */
+	#define MUL_ALG2 28	/* size for alternative multiply */
+	    config("mul2") == 28	/* was 1780 */
+	#define POW_ALG2 20	/* size for using REDC for powers */
+	    config("pow2") == 20	/* was 176 */
+	#define REDC_ALG2 25	/* size for using alternative REDC */
+	    config("redc2") == 25	/* was 220 */
+
+    The alg_config.cal script appears to be not correctly finding the
+    best REDC values.  While it has been improved, alg_config.cal still
+    seems to be suspect on how it attempts to find the best values.
+
+    Fixed an intro help file mistake found by Roger Hardiman
+    <roger at rjh dot org dot uk>.
+
+
+The following are the changes from calc version 2.12.5.0 to 2.12.5.1:
 
     Calc has a new calc-tester mailing list.  This list is for those
     who are using/testing calc.  We also use this list to announce
@@ -61,7 +91,7 @@ The following are the changes from calc version 2.12.5.0 to date:
     a general non-cryptographic quick hash.
 
 
-The following are the changes from calc version 2.12.4.14 to date:
+The following are the changes from calc version 2.12.4.14 to 2.12.5.0:
 
     For Apple OS X / Darwin target:
 
@@ -7106,8 +7136,8 @@ Following is a list of visible changes to calc from version 1.24.7 to 1.26.1:
 ## received a copy with calc; if not, write to Free Software Foundation, Inc.
 ## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 ##
-## @(#) $Revision: 30.46 $
-## @(#) $Id: CHANGES,v 30.46 2014/10/12 12:46:23 chongo Exp $
+## @(#) $Revision: 30.49 $
+## @(#) $Id: CHANGES,v 30.49 2016/02/06 08:42:57 chongo Exp $
 ## @(#) $Source: /usr/local/src/bin/calc/RCS/CHANGES,v $
 ##
 ## Under source code control:	1993/06/02 18:12:57
diff --git a/Makefile b/Makefile
index f90c9a1..f1bea82 100644
--- a/Makefile
+++ b/Makefile
@@ -39,8 +39,8 @@
 # received a copy with calc; if not, write to Free Software Foundation, Inc.
 # 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
 #
-MAKEFILE_REV= $$Revision: 30.78 $$
-# @(#) $Id: Makefile.ship,v 30.78 2014/10/06 08:45:06 chongo Exp $
+MAKEFILE_REV= $$Revision: 30.83 $$
+# @(#) $Id: Makefile.ship,v 30.83 2016/02/06 08:16:06 chongo Exp $
 # @(#) $Source: /usr/local/src/bin/calc/RCS/Makefile.ship,v $
 #
 # Under source code control:	1990/02/15 01:48:41
@@ -846,6 +846,15 @@ READLINE_EXTRAS=
 #READLINE_LIB= -L/sw/lib -lreadline
 #READLINE_EXTRAS= -lhistory -lncurses
 #
+# For Apple OS X: install homebrew and then:
+#
+#	brew install readline
+#
+# and use:
+#
+#READLINE_LIB= -L/usr/local/opt/readline/lib -lreadline
+#READLINE_EXTRAS= -lhistory -lncurses
+#
 READLINE_INCLUDE=
 #READLINE_INCLUDE= -I/usr/gnu/include
 #READLINE_INCLUDE= -I/usr/local/include
@@ -975,22 +984,13 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.5.0
+VERSION= 2.12.5.2
 
 # Names of shared libraries with versions
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
 
-# legacy partial versions are no longer used, only removed
-#
-VERS= 2.12.5
-VER= 2.12
-VE= 2
-LIB_EXT_VERS= ${LIB_EXT}.${VERS}
-LIB_EXT_VER= ${LIB_EXT}.${VER}
-LIB_EXT_VE= ${LIB_EXT}.${VE}
-
 # standard utilities used during make
 #
 SHELL= /bin/sh
@@ -1215,10 +1215,6 @@ CC= ${PURIFY} ${LCC} ${CCWERR}
 # Darwin dynamic shared lib filenames
 LIB_EXT:= .dylib
 LIB_EXT_VERSION:= .${VERSION}${LIB_EXT}
-# legacy partial versions are no longer used, only removed
-LIB_EXT_VERS:= .${VERS}${LIB_EXT}
-LIB_EXT_VER:= .${VER}${LIB_EXT}
-LIB_EXT_VE:= .${VE}${LIB_EXT}
 # LDCONFIG not required on this platform, so we redefine it to an empty string
 LDCONFIG:=
 # DARWIN_ARCH= -arch i386 -arch ppc	# Universal binary
@@ -1227,6 +1223,15 @@ LDCONFIG:=
 # DARWIN_ARCH= -arch x86_64		# native 64-bit binary
 DARWIN_ARCH=				# native binary
 #
+# Starting with El Capitan OS X 10.11, root by default could not
+# mkdir under system locations, so we now use the /opt/calc tree.
+#
+OPTDIR:= /opt/calc
+BINDIR:= /${OPTDIR}/bin
+LIBDIR:= /${OPTDIR}/lib
+CALC_SHAREDIR:= /${OPTDIR}/share
+CALC_INCDIR:= /${OPTDIR}/include
+SCRIPTDIR:= ${BINDIR}/cscript
 endif
 
 ##################
@@ -1771,9 +1776,6 @@ CUSTOM_PASSDOWN=  \
     TOUCH=${TOUCH} \
     TRUE=${TRUE} \
     VERSION=${VERSION} \
-    VERS=${VERS} \
-    VER=${VER} \
-    VE=${VE} \
     target=${target}
 
 # The complete list of Makefile vars passed down to help/Makefile.
@@ -1991,7 +1993,33 @@ TARGETS= ${EARLY_TARGETS} ${BLD_TYPE} ${LATE_TARGETS}
 #
 ###
 
-all: ${BLD_TYPE} CHANGES
+all: check_include ${BLD_TYPE} CHANGES
+
+check_include:
+	$(Q) if [ ! -d /usr/include ]; then \
+	    echo "ERROR: critical directory missing: /usr/include" 1>&2; \
+	    echo "Without this critical directory, we cannot compile." 1>&2; \
+	    echo 1>&2; \
+	    echo "Perhaps your system isn't setup to compile C source?" 1>&2; \
+	    echo "For example, Apple OS X / darwin requres that XCode" 1>&2; \
+	    echo "must be installed and that you run the command:" 1>&2; \
+	    echo 1>&2; \
+	    echo "    xcode-select --install" 1>&2; \
+	    echo 1>&2; \
+	    exit 1; \
+	fi
+	$(Q) if [ ! -f /usr/include/stdio.h ]; then \
+	    echo "ERROR: critical include files are missing" 1>&2; \
+	    echo "Without this critical directory, we cannot compile." 1>&2; \
+	    echo 1>&2; \
+	    echo "Perhaps your system isn't setup to compile C source?" 1>&2; \
+	    echo "For example, Apple OS X / darwin requres that XCode" 1>&2; \
+	    echo "must be installed and that you run the command:" 1>&2; \
+	    echo 1>&2; \
+	    echo "    xcode-select --install" 1>&2; \
+	    echo 1>&2; \
+	    exit 1; \
+	fi
 
 prep:
 	${Q} ${MAKE} -f ${MAKE_FILE} all DEBUG='-g3'
@@ -4256,12 +4284,6 @@ clobber: custom/Makefile clean
 	cd cscript; ${RM} -f all; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo remove files that are obsolete
-	${RM} -f libcalc${LIB_EXT_VERS}
-	${RM} -f libcalc${LIB_EXT_VER}
-	${RM} -f libcalc${LIB_EXT_VE}
-	${RM} -f libcustcalc${LIB_EXT_VERS}
-	${RM} -f libcustcalc${LIB_EXT_VER}
-	${RM} -f libcustcalc${LIB_EXT_VE}
 	${RM} -rf win32 build
 	${RM} -f no_implicit.arg
 	${RM} -f no_implicit.c no_implicit.o no_implicit${EXT}
@@ -4466,27 +4488,6 @@ endif
 	    ${MV} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}.new \
 	    	     ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}"; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VERS}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VER}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VER}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VE}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VE}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-		fi; \
-	    fi; \
 	    ${LN} -f -s libcalc${LIB_EXT_VERSION} \
 	    		${T}${LIBDIR}/libcalc${LIB_EXT}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
@@ -4497,27 +4498,6 @@ endif
 	    ${MV} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}.new \
 	    	     ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}; \
 	    echo "installed ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}"; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VERS}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VER}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VE}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-		fi; \
-	    fi; \
 	    ${LN} -f -s libcustcalc${LIB_EXT_VERSION} \
 	    		${T}${LIBDIR}/libcustcalc${LIB_EXT}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
@@ -4655,32 +4635,6 @@ uninstall: custom/Makefile
 		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT}"; \
 	    fi; \
 	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}";\
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-		echo -n "cannot uninstall "; \
-		echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-		echo \
-		  "cannot uninstall ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    fi; \
-	fi
 	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}" ]; then \
 	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}"; \
 	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}" ]; then \
@@ -4698,30 +4652,6 @@ uninstall: custom/Makefile
 		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
 	    fi; \
 	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    fi; \
-	fi
 	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}" ]; then \
 	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}"; \
 	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}" ]; then \
diff --git a/Makefile.simple b/Makefile.simple
index 63ecea4..edb286c 100644
--- a/Makefile.simple
+++ b/Makefile.simple
@@ -39,8 +39,8 @@
 # received a copy with calc; if not, write to Free Software Foundation, Inc.
 # 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.
 #
-MAKEFILE_REV= $$Revision: 30.78 $$
-# @(#) $Id: Makefile.ship,v 30.78 2014/10/06 08:45:06 chongo Exp $
+MAKEFILE_REV= $$Revision: 30.83 $$
+# @(#) $Id: Makefile.ship,v 30.83 2016/02/06 08:16:06 chongo Exp $
 # @(#) $Source: /usr/local/src/bin/calc/RCS/Makefile.ship,v $
 #
 # Under source code control:	1990/02/15 01:48:41
@@ -823,6 +823,15 @@ READLINE_EXTRAS=
 #READLINE_LIB= -L/sw/lib -lreadline
 #READLINE_EXTRAS= -lhistory -lncurses
 #
+# For Apple OS X: install homebrew and then:
+#
+#	brew install readline
+#
+# and use:
+#
+#READLINE_LIB= -L/usr/local/opt/readline/lib -lreadline
+#READLINE_EXTRAS= -lhistory -lncurses
+#
 READLINE_INCLUDE=
 #READLINE_INCLUDE= -I/usr/gnu/include
 #READLINE_INCLUDE= -I/usr/local/include
@@ -952,22 +961,13 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.5.0
+VERSION= 2.12.5.2
 
 # Names of shared libraries with versions
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
 
-# legacy partial versions are no longer used, only removed
-#
-VERS= 2.12.5
-VER= 2.12
-VE= 2
-LIB_EXT_VERS= ${LIB_EXT}.${VERS}
-LIB_EXT_VER= ${LIB_EXT}.${VER}
-LIB_EXT_VE= ${LIB_EXT}.${VE}
-
 # standard utilities used during make
 #
 SHELL= /bin/sh
@@ -1347,9 +1347,6 @@ CUSTOM_PASSDOWN=  \
     TOUCH=${TOUCH} \
     TRUE=${TRUE} \
     VERSION=${VERSION} \
-    VERS=${VERS} \
-    VER=${VER} \
-    VE=${VE} \
     target=${target}
 
 # The complete list of Makefile vars passed down to help/Makefile.
@@ -1535,7 +1532,33 @@ TARGETS= ${EARLY_TARGETS} ${BLD_TYPE} ${LATE_TARGETS}
 #
 ###
 
-all: ${BLD_TYPE} CHANGES
+all: check_include ${BLD_TYPE} CHANGES
+
+check_include:
+	$(Q) if [ ! -d /usr/include ]; then \
+	    echo "ERROR: critical directory missing: /usr/include" 1>&2; \
+	    echo "Without this critical directory, we cannot compile." 1>&2; \
+	    echo 1>&2; \
+	    echo "Perhaps your system isn't setup to compile C source?" 1>&2; \
+	    echo "For example, Apple OS X / darwin requres that XCode" 1>&2; \
+	    echo "must be installed and that you run the command:" 1>&2; \
+	    echo 1>&2; \
+	    echo "    xcode-select --install" 1>&2; \
+	    echo 1>&2; \
+	    exit 1; \
+	fi
+	$(Q) if [ ! -f /usr/include/stdio.h ]; then \
+	    echo "ERROR: critical include files are missing" 1>&2; \
+	    echo "Without this critical directory, we cannot compile." 1>&2; \
+	    echo 1>&2; \
+	    echo "Perhaps your system isn't setup to compile C source?" 1>&2; \
+	    echo "For example, Apple OS X / darwin requres that XCode" 1>&2; \
+	    echo "must be installed and that you run the command:" 1>&2; \
+	    echo 1>&2; \
+	    echo "    xcode-select --install" 1>&2; \
+	    echo 1>&2; \
+	    exit 1; \
+	fi
 
 prep:
 	${Q} ${MAKE} -f ${MAKE_FILE} all DEBUG='-g3'
@@ -3756,12 +3779,6 @@ clobber: custom/Makefile clean
 	cd cscript; ${RM} -f all; ${MAKE} -f Makefile ${CSCRIPT_PASSDOWN} $@
 	${V} echo '=-=-=-=-= Back to the main Makefile for $@ rule =-=-=-=-='
 	${V} echo remove files that are obsolete
-	${RM} -f libcalc${LIB_EXT_VERS}
-	${RM} -f libcalc${LIB_EXT_VER}
-	${RM} -f libcalc${LIB_EXT_VE}
-	${RM} -f libcustcalc${LIB_EXT_VERS}
-	${RM} -f libcustcalc${LIB_EXT_VER}
-	${RM} -f libcustcalc${LIB_EXT_VE}
 	${RM} -rf win32 build
 	${RM} -f no_implicit.arg
 	${RM} -f no_implicit.c no_implicit.o no_implicit${EXT}
@@ -3949,27 +3966,6 @@ install: custom/Makefile ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all
 	    ${MV} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}.new \
 	    	     ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}"; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VERS}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VER}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VER}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VE}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcalc${LIB_EXT_VE}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-		fi; \
-	    fi; \
 	    ${LN} -f -s libcalc${LIB_EXT_VERSION} \
 	    		${T}${LIBDIR}/libcalc${LIB_EXT}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
@@ -3980,27 +3976,6 @@ install: custom/Makefile ${LIB_H_SRC} ${BUILD_H_SRC} calc.1 all
 	    ${MV} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}.new \
 	    	     ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}; \
 	    echo "installed ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}"; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VERS}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VER}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-		fi; \
-	    fi; \
-	    if [ "${LIB_EXT_VERSION}" != "${LIB_EXT_VE}" ]; then \
-		if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-		    ${RM} -f ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}; \
-		    echo -n "removed legacy and likely out of date: "; \
-		    echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-		fi; \
-	    fi; \
 	    ${LN} -f -s libcustcalc${LIB_EXT_VERSION} \
 	    		${T}${LIBDIR}/libcustcalc${LIB_EXT}; \
 	    echo "installed ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
@@ -4138,32 +4113,6 @@ uninstall: custom/Makefile
 		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT}"; \
 	    fi; \
 	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}";\
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VE}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}" ]; then \
-		echo -n "cannot uninstall "; \
-		echo "${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VER}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}" ]; then \
-		echo \
-		  "cannot uninstall ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcustcalc${LIB_EXT_VERS}"; \
-	    fi; \
-	fi
 	-${Q} if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}" ]; then \
 	    ${RM} -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}"; \
 	    if [ -f "${T}${LIBDIR}/libcustcalc${LIB_EXT_VERSION}" ]; then \
@@ -4181,30 +4130,6 @@ uninstall: custom/Makefile
 		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT}"; \
 	    fi; \
 	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VE}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VE}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VER}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VER}"; \
-	    fi; \
-	fi
-	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERS}" ]; then \
-		echo "cannot uninstall ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    else \
-		echo "uninstalled ${T}${LIBDIR}/libcalc${LIB_EXT_VERS}"; \
-	    fi; \
-	fi
 	-${Q} if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}" ]; then \
 	    ${RM} -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}"; \
 	    if [ -f "${T}${LIBDIR}/libcalc${LIB_EXT_VERSION}" ]; then \
diff --git a/cal/alg_config.cal b/cal/alg_config.cal
index f16da6f..0994abe 100644
--- a/cal/alg_config.cal
+++ b/cal/alg_config.cal
@@ -17,8 +17,8 @@
  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
- * @(#) $Revision: 30.11 $
- * @(#) $Id: alg_config.cal,v 30.11 2014/09/07 06:13:04 chongo Exp $
+ * @(#) $Revision: 30.12 $
+ * @(#) $Id: alg_config.cal,v 30.12 2016/02/06 08:38:56 chongo Exp $
  * @(#) $Source: /usr/local/src/bin/calc/cal/RCS/alg_config.cal,v $
  *
  * Under source code control:	2006/06/07 14:10:11
@@ -364,7 +364,8 @@ define best_mul2()
     /*
      * setup
      */
-    test_time = 30.0;
+    printf("WARNING: This tool may not be computing the correct best value\n");
+    test_time = 5.0;
     printf("The best_mul2() function will take a LONG time to run!\n");
     printf("It is important that best_mul2() run on an othwewise idle host!\n");
     if (config("user_debug") <= 0) {
@@ -376,7 +377,7 @@ define best_mul2()
     /*
      * firewall - must have a >1 ratio for the initial length
      */
-    high = 16;
+    high = 8;
     best_val = high;
     if (config("user_debug") > 0) {
 	printf("testing multiply alg1/alg2 ratio for len = %d\n", high);
@@ -400,7 +401,7 @@ define best_mul2()
 	 * We will multiplicatively expand our test level until
 	 * the ratio drops below 1.0.
 	 */
-	expand = ((ratio >= 10) ? 1024 : 2^round(ratio));
+	expand = 2;
 	low = high;
 	high *= expand;
 	if (config("user_debug") > 1) {
@@ -844,7 +845,8 @@ define best_sq2()
     /*
      * setup
      */
-    test_time = 30.0;
+    printf("WARNING: This tool may not be computing the correct best value\n");
+    test_time = 5.0;
     printf("The best_sq2() function will take a LONG time to run!\n");
     printf("It is important that best_sq2() run on an othwewise idle host!\n");
     if (config("user_debug") <= 0) {
@@ -856,7 +858,7 @@ define best_sq2()
     /*
      * firewall - must have a >1 ratio for the initial length
      */
-    high = 16;
+    high = 8;
     best_val = high;
     if (config("user_debug") > 0) {
 	printf("testing square alg1/alg2 ratio for len = %d\n", high);
@@ -880,7 +882,7 @@ define best_sq2()
 	 * We will multiplicatively expand our test level until
 	 * the ratio drops below 1.0.
 	 */
-	expand = ((ratio >= 10) ? 1024 : 2^round(ratio));
+	expand = 2;
 	low = high;
 	high *= expand;
 	if (config("user_debug") > 1) {
@@ -1346,6 +1348,7 @@ define best_pow2()
     /*
      * setup
      */
+    printf("WARNING: This tool may not be computing the correct best value\n");
     test_time = 60.0;
     printf("The best_pow2() function will take a LONG time to run!\n");
     printf("It is important that best_pow2() run on an othwewise idle host!\n");
diff --git a/cal/regress.cal b/cal/regress.cal
index 5a5431a..17444c6 100644
--- a/cal/regress.cal
+++ b/cal/regress.cal
@@ -17,8 +17,8 @@
  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
- * @(#) $Revision: 30.12 $
- * @(#) $Id: regress.cal,v 30.12 2013/09/02 02:32:55 chongo Exp $
+ * @(#) $Revision: 30.13 $
+ * @(#) $Id: regress.cal,v 30.13 2016/02/06 08:39:35 chongo Exp $
  * @(#) $Source: /usr/local/src/bin/calc/cal/RCS/regress.cal,v $
  *
  * Under source code control:	1990/02/15 01:50:36
@@ -403,14 +403,14 @@ define test_config()
 					'512: config("trace") == 0');
 	vrfy(config("maxprint") == 16,
 					'513: config("maxprint") == 16');
-	vrfy(config("mul2") == 1780,
-					'514: config("mul2") == 1780');
-	vrfy(config("sq2") == 3388,
-					'515: config("sq2") == 3388');
-	vrfy(config("pow2") == 176,
-					'516: config("pow2") == 176');
-	vrfy(config("redc2") == 220,
-					'517: config("redc2") == 220');
+	vrfy(config("mul2") == 28,
+					'514: config("mul2") == 28');
+	vrfy(config("sq2") == 28,
+					'515: config("sq2") == 28');
+	vrfy(config("pow2") == 20,
+					'516: config("pow2") == 20');
+	vrfy(config("redc2") == 25,
+					'517: config("redc2") == 25');
 	vrfy(config("tilde"),
 					'518: config("tilde")');
 	vrfy(config("tab"),
diff --git a/custom/Makefile b/custom/Makefile
index ddc3022..0e56fdf 100644
--- a/custom/Makefile
+++ b/custom/Makefile
@@ -18,8 +18,8 @@
 # received a copy with calc; if not, write to Free Software Foundation, Inc.
 # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
-# @(#) $Revision: 30.36 $
-# @(#) $Id: Makefile.head,v 30.36 2014/09/30 00:03:05 chongo Exp $
+# @(#) $Revision: 30.39 $
+# @(#) $Id: Makefile.head,v 30.39 2016/01/17 09:02:17 chongo Exp $
 # @(#) $Source: /usr/local/src/bin/calc/custom/RCS/Makefile.head,v $
 #
 # Under source code control:	1997/03/09 02:28:54
@@ -352,22 +352,13 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.5.0
+VERSION= 2.12.5.2
 
 # Names of shared libraries with versions
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
 
-# legacy partial versions are no longer used, only removed
-#
-VERS= 2.12.5
-VER= 2.12
-VE= 2
-LIB_EXT_VERS= ${LIB_EXT}.${VERS}
-LIB_EXT_VER= ${LIB_EXT}.${VER}
-LIB_EXT_VE= ${LIB_EXT}.${VE}
-
 # standard tools
 #
 SHELL= /bin/sh
@@ -599,10 +590,6 @@ CC= ${PURIFY} ${LCC} ${CCWERR}
 # Darwin dynamic shared lib filenames
 LIB_EXT:= .dylib
 LIB_EXT_VERSION:= .${VERSION}${LIB_EXT}
-# legacy partial versions are no longer used, only removed
-LIB_EXT_VERS:= .${VERS}${LIB_EXT}
-LIB_EXT_VER:= .${VER}${LIB_EXT}
-LIB_EXT_VE:= .${VE}${LIB_EXT}
 # LDCONFIG not required on this platform, so we redefine it to an empty string
 LDCONFIG:=
 # DARWIN_ARCH= -arch i386 -arch ppc	# Universal binary
@@ -611,6 +598,15 @@ LDCONFIG:=
 # DARWIN_ARCH= -arch x86_64		# native 64-bit binary
 DARWIN_ARCH=				# native binary
 #
+# Starting with El Capitan OS X 10.11, root by default could not
+# mkdir under system locations, so we now use the /opt/calc tree.
+#
+OPTDIR:= /opt/calc
+BINDIR:= /${OPTDIR}/bin
+LIBDIR:= /${OPTDIR}/lib
+CALC_SHAREDIR:= /${OPTDIR}/share
+CALC_INCDIR:= /${OPTDIR}/include
+SCRIPTDIR:= ${BINDIR}/cscript
 endif
 
 ##################
@@ -1243,9 +1239,6 @@ clobber: clean
 	${RM} -f libcustcalc.*.dylib
 	${RM} -f libcustcalc.a
 	${V} echo remove files that are obsolete
-	${RM} -f libcustcalc${LIB_EXT_VERS}
-	${RM} -f libcustcalc${LIB_EXT_VER}
-	${RM} -f libcustcalc${LIB_EXT_VE}
 #if 0	/* start of skip for non-Gnu makefiles */
 	${RM} -f Makefile.simple
 #endif	/* end of skip for non-Gnu makefiles */
diff --git a/custom/Makefile.head b/custom/Makefile.head
index b94c936..f80205e 100644
--- a/custom/Makefile.head
+++ b/custom/Makefile.head
@@ -18,8 +18,8 @@
 # received a copy with calc; if not, write to Free Software Foundation, Inc.
 # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
-# @(#) $Revision: 30.36 $
-# @(#) $Id: Makefile.head,v 30.36 2014/09/30 00:03:05 chongo Exp $
+# @(#) $Revision: 30.39 $
+# @(#) $Id: Makefile.head,v 30.39 2016/01/17 09:02:17 chongo Exp $
 # @(#) $Source: /usr/local/src/bin/calc/custom/RCS/Makefile.head,v $
 #
 # Under source code control:	1997/03/09 02:28:54
@@ -352,22 +352,13 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.5.0
+VERSION= 2.12.5.2
 
 # Names of shared libraries with versions
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
 
-# legacy partial versions are no longer used, only removed
-#
-VERS= 2.12.5
-VER= 2.12
-VE= 2
-LIB_EXT_VERS= ${LIB_EXT}.${VERS}
-LIB_EXT_VER= ${LIB_EXT}.${VER}
-LIB_EXT_VE= ${LIB_EXT}.${VE}
-
 # standard tools
 #
 SHELL= /bin/sh
diff --git a/custom/Makefile.simple b/custom/Makefile.simple
index 2adc986..a201af6 100644
--- a/custom/Makefile.simple
+++ b/custom/Makefile.simple
@@ -18,8 +18,8 @@
 # received a copy with calc; if not, write to Free Software Foundation, Inc.
 # 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
-# @(#) $Revision: 30.36 $
-# @(#) $Id: Makefile.head,v 30.36 2014/09/30 00:03:05 chongo Exp $
+# @(#) $Revision: 30.39 $
+# @(#) $Id: Makefile.head,v 30.39 2016/01/17 09:02:17 chongo Exp $
 # @(#) $Source: /usr/local/src/bin/calc/custom/RCS/Makefile.head,v $
 #
 # Under source code control:	1997/03/09 02:28:54
@@ -337,22 +337,13 @@ EXT=
 
 # The default calc versions
 #
-VERSION= 2.12.5.0
+VERSION= 2.12.5.2
 
 # Names of shared libraries with versions
 #
 LIB_EXT= .so
 LIB_EXT_VERSION= ${LIB_EXT}.${VERSION}
 
-# legacy partial versions are no longer used, only removed
-#
-VERS= 2.12.5
-VER= 2.12
-VE= 2
-LIB_EXT_VERS= ${LIB_EXT}.${VERS}
-LIB_EXT_VER= ${LIB_EXT}.${VER}
-LIB_EXT_VE= ${LIB_EXT}.${VE}
-
 # standard tools
 #
 SHELL= /bin/sh
@@ -798,9 +789,6 @@ clobber: clean
 	${RM} -f libcustcalc.*.dylib
 	${RM} -f libcustcalc.a
 	${V} echo remove files that are obsolete
-	${RM} -f libcustcalc${LIB_EXT_VERS}
-	${RM} -f libcustcalc${LIB_EXT_VER}
-	${RM} -f libcustcalc${LIB_EXT_VE}
 
 # install everything
 #
diff --git a/custom/Makefile.tail b/custom/Makefile.tail
index 6753bb7..c1c8800 100644
--- a/custom/Makefile.tail
+++ b/custom/Makefile.tail
@@ -293,9 +293,6 @@ clobber: clean
 	${RM} -f libcustcalc.*.dylib
 	${RM} -f libcustcalc.a
 	${V} echo remove files that are obsolete
-	${RM} -f libcustcalc${LIB_EXT_VERS}
-	${RM} -f libcustcalc${LIB_EXT_VER}
-	${RM} -f libcustcalc${LIB_EXT_VE}
 #if 0	/* start of skip for non-Gnu makefiles */
 	${RM} -f Makefile.simple
 #endif	/* end of skip for non-Gnu makefiles */
diff --git a/help/intro b/help/intro
index d4d8797..ab79196 100644
--- a/help/intro
+++ b/help/intro
@@ -54,7 +54,7 @@ What is calc?
 
     Functions can be used in expressions.  There are a great number of
     pre-defined functions.  For example, the following will calculate
-    the factorial of the value of 'old':
+    the factorial of the value of 'whey':
 
 	    fact(whey)
 
@@ -185,8 +185,8 @@ What is calc?
 ## received a copy with calc; if not, write to Free Software Foundation, Inc.
 ## 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 ##
-## @(#) $Revision: 30.1 $
-## @(#) $Id: intro,v 30.1 2007/03/16 11:10:42 chongo Exp $
+## @(#) $Revision: 30.2 $
+## @(#) $Id: intro,v 30.2 2016/02/06 08:25:30 chongo Exp $
 ## @(#) $Source: /usr/local/src/bin/calc/help/RCS/intro,v $
 ##
 ## Under source code control:	1991/07/21 04:37:21
diff --git a/version.c b/version.c
index 8ddb3f6..7dc04d8 100644
--- a/version.c
+++ b/version.c
@@ -19,8 +19,8 @@
  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
- * @(#) $Revision: 30.27 $
- * @(#) $Id: version.c,v 30.27 2014/10/12 12:44:57 chongo Exp $
+ * @(#) $Revision: 30.29 $
+ * @(#) $Id: version.c,v 30.29 2016/02/06 08:42:57 chongo Exp $
  * @(#) $Source: /usr/local/src/bin/calc/RCS/version.c,v $
  *
  * Under source code control:	1990/05/22 11:00:58
@@ -49,7 +49,7 @@ static char *program;
 #define MAJOR_VER	2	/* major library version */
 #define MINOR_VER	12	/* minor library version */
 #define MAJOR_PATCH	5	/* major software level under library version */
-#define MINOR_PATCH	0	/* minor software level or 0 if not patched */
+#define MINOR_PATCH	2	/* minor software level or 0 if not patched */
 
 
 /*
diff --git a/zmath.h b/zmath.h
index bf203f2..42a3e01 100644
--- a/zmath.h
+++ b/zmath.h
@@ -17,8 +17,8 @@
  * received a copy with calc; if not, write to Free Software Foundation, Inc.
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
- * @(#) $Revision: 30.6 $
- * @(#) $Id: zmath.h,v 30.6 2014/09/30 00:55:11 chongo Exp $
+ * @(#) $Revision: 30.7 $
+ * @(#) $Id: zmath.h,v 30.7 2016/02/06 08:39:35 chongo Exp $
  * @(#) $Source: /usr/local/src/bin/calc/RCS/zmath.h,v $
  *
  * Under source code control:	1993/07/30 19:42:48
@@ -229,12 +229,12 @@ typedef SB32 LEN;			/* unit of length storage */
 #define MAXLEN	((LEN) 0x7fffffff >> 3) /* longest value allowed */
 
 
-#define MAXREDC 64			/* number of entries in REDC cache */
-#define SQ_ALG2 3388			/* size for alternative squaring */
-#define MUL_ALG2 1780			/* size for alternative multiply */
-#define POW_ALG2 176			/* size for using REDC for powers */
+#define MAXREDC 256			/* number of entries in REDC cache */
+#define SQ_ALG2 28			/* size for alternative squaring */
+#define MUL_ALG2 28			/* size for alternative multiply */
+#define POW_ALG2 20			/* size for using REDC for powers */
 /* old REDC_ALG2 was 5/4 of POW_ALG2, so we will keep the same ratio */
-#define REDC_ALG2 220			/* size for using alternative REDC */
+#define REDC_ALG2 25			/* size for using alternative REDC */
 
 
 typedef union {