Function: _--
Section: symbolic_operators
C-Name: gsub1e
Prototype: &
Help: x--: set x to x-1.
Description:
(*bptr):bptr --$1
(*small):small --$1
(*lg):lg --$1
(*int):int:parens $1 = subis($1, 1)
(*real):real:parens $1 = subrs($1, 1)
(*mp):mp:parens $1 = mpsub($1, gen_1)
(*pol):pol:parens $1 = gsubgs($1, 1)
(*gen):gen:parens $1 = gsubgs($1, 1)