Function: lift
Section: conversions
C-Name: lift0
Prototype: GDn
Help: lift(x,{v}): lifts every element of Z/nZ to Z or T[x]/PT[x] to T[x]
 for a type T if v is omitted, otherwise lift only polymods with main
 variable v. If v does not occur in x, lift only intmods
Description: 
 (pol):pol	lift($1)
 (vec):vec	lift($1)
 (gen):gen	lift($1)
 (pol, var):pol	lift0($1, $2)
 (vec, var):vec	lift0($1, $2)
 (gen, var):gen	lift0($1, $2)

