prolog::genarg0/3

genarg0( +Index, +Term , -Arg )*

Similar to genarg//33, but genarg0(0,_T_,_F_) unifies F with T's principal functor: ```

?- genarg0(I,f(a,b),A). A = f, I = 0 ? ; A = a, I = 1 ? ; A = b, I = 2. ```

Private-func:

1. prolog::genarg0_3::genarg0/3(int ARG1, int ARG2, int ARG3)():