Theorem elv ≪ | index | src | ≫

theorem elv (a: nat): $ a e. _V $;

Step	Hyp	Ref	Expression
1		biidd	x = a -> (T. <-> T.)
2	1	elabe	a e. {x \| T.} <-> T.
3	2	conv Univ	a e. _V <-> T.
4		itru	T.
5	3, 4	mpbir	a e. _V

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp, itru), axs_pred_calc (ax_gen, ax_4, ax_5, ax_6, ax_7, ax_10, ax_11, ax_12), axs_set (elab, ax_8)