print_goalstack : goalstack -> unit

SYNOPSIS: Print a goalstack.
DESCRIPTION: print_goalstack gs prints the goalstack gs to standard output, with no following newline.
FAILURE CONDITIONS: Never fails.
COMMENTS: This is invoked automatically when something of type goalstack is produced at the top level, so manual invocation is not normally needed.
SEE ALSO: print_goal, print_term, PRINT_GOAL_TAC.