copy_term/4

Availability:built-in

copy_term(+VarsIn, +In, -VarsOut, -Out)

Similar to copy_term/2, but only rename the variables in VarsIn that appear in In.^{120This
predicate is based on a similar predicate in s(CASP) by Joaquin Arias.} Variables in In that do not appear in VarsIn are shared between In and Out. Sub terms that only contain such shared variables are shared as a whole between In and Out. VarsIn is often a list, but can be an arbitrary term. For example:

?- copy_term([X], q(X,Y), Vars, Term).
Vars = [_A],
Term = q(_A, Y).

Note that if VarsIn and In do not share any variables, Out is equivalent to In and VarsOut is a copy (as copy_term/2) of VarsIn. If In does not contain any variables not in VarsIn the result is the same as copy_term(VarsIn-In, VarsOut-Out).