Theorem boolle1 ≪ | index | src | ≫

theorem boolle1 (n: nat): $ bool n <-> n <= 1 $;

Step	Hyp	Ref	Expression
1		bicom	(n <= 1 <-> bool n) -> (bool n <-> n <= 1)
2		leltsuc	n <= 1 <-> n < suc 1
3	2	conv bool, d2	n <= 1 <-> bool n
4	1, 3	ax_mp	bool n <-> n <= 1

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_peano (peano2, peano5, addeq, add0, addS)