Function: pollead
Section: polynomials
C-Name: pollead
Prototype: GDn
Help: pollead(x,{v}): leading coefficient of polynomial or series x, or x
 itself if x is a scalar. Error otherwise. With respect to the main variable
 of x if v is omitted, with respect to the variable v otherwise
Description: 
 (pol):gen:copy         leading_term($1)
 (gen):gen              pollead($1, -1)
 (gen, var):gen         pollead($1, $2)

