Theorem eqb0 | index | src |

theorem eqb0 (n: nat): $ ~odd n <-> n = b0 (n // 2) $;
StepHypRefExpression
1 con1
(~n = b0 (n // 2) -> odd n) -> ~odd n -> n = b0 (n // 2)
2 b0orb1
n = b0 (n // 2) \/ n = b1 (n // 2)
3 2 conv or
~n = b0 (n // 2) -> n = b1 (n // 2)
4 b1odd
odd (b1 (n // 2))
5 oddeq
n = b1 (n // 2) -> (odd n <-> odd (b1 (n // 2)))
6 4, 5 mpbiri
n = b1 (n // 2) -> odd n
7 3, 6 rsyl
~n = b0 (n // 2) -> odd n
8 1, 7 ax_mp
~odd n -> n = b0 (n // 2)
9 b0odd
~odd (b0 (n // 2))
10 oddeq
n = b0 (n // 2) -> (odd n <-> odd (b0 (n // 2)))
11 10 noteqd
n = b0 (n // 2) -> (~odd n <-> ~odd (b0 (n // 2)))
12 9, 11 mpbiri
n = b0 (n // 2) -> ~odd n
13 8, 12 ibii
~odd n <-> n = b0 (n // 2)

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), axs_the (theid, the0), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)