NAME
    ismat - whether a value is a matrix

SYNOPSIS
    ismat(x)

TYPES
    x		any, &any

    return	int

DESCRIPTION
    Determine if x is a matrix.  This function will return 1 if x is
    a matrix, 0 otherwise.

EXAMPLE
    > mat a[2]
    > print ismat(a), ismat(1)
    1 0

LIMITS
    none

LIBRARY
    none

SEE ALSO
    mat, matdim, matfill, matmax, matmin, matsum, mattrans,
    isassoc, isatty, isblk, isconfig, isdefined, iserror, iseven, isfile,
    ishash, isident, isint, islist, ismult, isnull, isnum, isobj,
    isobjtype, isodd, isprime, isrand, israndom, isreal, isrel,
    issimple, issq, isstr, istype