Theorem Taileq ≪ | index | src | ≫

theorem Taileq (_S1 _S2: set): $ _S1 == _S2 -> Tail _S1 == Tail _S2 $;

Step	Hyp	Ref	Expression
1		id	_S1 == _S2 -> _S1 == _S2
2	1	Taileqd	_S1 == _S2 -> Tail _S1 == Tail _S2

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)