mtx_errors. :- multifile( pack_errors:message/3 ). pack_errors:message( non_canonical(Type) ) --> ['Input matrix in canonical representation expected, found: ~w'-[Type]]. pack_errors:message( unknown_mtx_input(Spec,Instance,Opts) ) --> ['Cannot convert input : ~w, (having groundness spec:~w) and, \n options: ~w'-[Instance,Spec,Opts]]. pack_errors:message( handle_inconsistency(Handle) ) --> ['Cache handle: ~w exists, but data not found for it.'-[Handle]]. pack_errors:message( handle_exists(Handle,OthF,AbsF) ) --> ['Cache handle: ~w exists but points to: ~p, refusingto repoint to: ~w.'-[Handle,OthF,AbsF]].