mode_inf.m:014: In clause for `p(out, out)':
mode_inf.m:014:   in call to predicate `mode_inf.q'/2:
mode_inf.m:014:   mode error: arguments `X, Y' have the following insts:
mode_inf.m:014:     free,
mode_inf.m:014:     free
mode_inf.m:014:   which does not match any of the valid modes for the callee
mode_inf.m:014:   (predicate `mode_inf.q'/2)
mode_inf.m:014:   because of the following error.
mode_inf.m:016: In clause for `q(out(not_reached), out(not_reached))':
mode_inf.m:016:   in argument 2 of clause head:
mode_inf.m:016:   mode error in unification of `Z' and `Z'.
mode_inf.m:016:   Variable `Z' has instantiatedness `free',
mode_inf.m:016:   variable `Z' has instantiatedness `free'.
mode_inf.m:016: REJECTED :- mode q(out(...), out(...)).