Function: whatnow
Class: gp
Section: programming/specific
C-Name: whatnow0
Prototype: vr
Help: whatnow(key): if key was present in GP version 1.39.15, gives
 the new function name.
Description:
 (str):void             whatnow($1, 0)
Doc: if keyword \var{key} is the name of a function that was present in GP
 version 1.39.15, outputs the new function name and syntax, if it
 changed at all. Functions that where introduced since then, then modified
 are also recognized.
 \bprog
 ? whatnow("mu")
 New syntax: mu(n) ===> moebius(n)

 moebius(x): Moebius function of x.

 ? whatnow("sin")
 This function did not change
 @eprog When a function was removed and the underlying functionality
 is not available under a compatible interface, no equivalent is mentioned:
 \bprog
 ? whatnow("buchfu")
 This function no longer exists
 @eprog\noindent (The closest equivalent would be to set \kbd{K = bnfinit(T)}
 then access \kbd{K.fu}.)