print_tac
goalStack.print_tac : string -> tactic
Prints the goal; does not change it.
The tactic print_tac s
prints the string s
followed by (the pretty-printed string of) the goal to which it is
applied (using the standard SML print
function). The effect
on the goal is as if the tactic ALL_TAC
had been applied
(i.e., the state of the goal is not changed).
Never fails.
This is useful for debugging tactic applications in contexts where the usual interactive goal-stack is not available.