Release calc version 2.10.2t30

help/head

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+NAME
+    head - create a list of specified size from the head of a list
+
+SYNOPSIS
+    head(x, y)
+
+TYPES
+    x		list
+    y		int
+
+    return	list
+
+DESCRIPTION
+    If 0 <= y <= size(x), head(x,y) returns a list of size y whose
+    elements in succession have values x[[0]]. x[[1]], ..., x[[y - 1]].
+
+    If y > size(x), head(x,y) is a copy of x.
+
+    If -size(x) < y < 0, head(x,y) returns a list of size (size(x) + y)
+    whose elements in succession have values x[[0]]. x[[1]], ...,
+    i.e. a copy of x from which the last -y members have been deleted.
+
+    If y <= -size(x), head(x,y) returns a list with no members.
+
+    For any integer y, x == join(head(x,y), tail(x,-y)).
+
+EXAMPLE
+    > A = list(2, 3, 5, 7, 11)
+    > head(A, 2)
+
+    list (2 members, 2 nonzero):
+	  [[0]] = 2
+	  [[1]] = 3
+
+    > head(A, -2)
+
+    list (3 members, 3 nonzero):
+	  [[0]] = 2
+	  [[1]] = 3
+	  [[2]] = 5
+
+LIMITS
+    none
+
+LIBRARY
+    none
+
+SEE ALSO
+    tail, segment