Loads an axiom from a given theory segment of the current theory.
DESCRIBE
A call of axiom "thy" "ax" returns axiom ax from the theory segment thy.
The theory segment thy must be part of the current theory. The name ax is
the name given to the axiom by the user when it was originally added to the
theory segment (by a call to new_axiom). The name of the current theory
segment can be abbreviated by "-".
FAILURE
The call axiom "thy" "ax" will fail if the theory segment thy is not part
of the current theory. It will also fail if there does not exist an axiom of
name ax in theory segment thy.
EXAMPLE
- axiom "bool" "BOOL_CASES_AX";
val it = |- !t. (t = T) \/ (t = F) : thm