Function: truncate
Section: conversions
C-Name: trunc0
Prototype: GD&
Help: truncate(x,{&e}): truncation of x; when x is a power series,take away
 the O(X^). If e is present, do not take into account loss of integer part
 precision, and set e = error estimate in bits
Description: 
 (small):small:parens   $1
 (int):int:copy:parens  $1
 (real):int             truncr($1)
 (mp):int               mptrunc($1)
 (mp, &small):int       gcvtoi($1, &$2)
 (mp, &int):int         trunc0($1, &$2)
 (gen):gen              gtrunc($1)
 (gen, &small):gen      gcvtoi($1, &$2)
 (gen, &int):gen        trunc0($1, &$2)

