trailed_mutable.m:019: In clause for predicate `initialise_mutable_global2'/0:
trailed_mutable.m:019:   in argument 1 of call to predicate
trailed_mutable.m:019:   `trailed_mutable.set_global2'/1:
trailed_mutable.m:019:   type error: variable `X' has type
trailed_mutable.m:019:     float;
trailed_mutable.m:019:   expected type was
trailed_mutable.m:019:     int.
For more information, recompile with `-E'.