Theorem boolodd | index | src |

theorem boolodd (n: nat): $ bool n -> (odd n <-> true n) $;
StepHypRefExpression
1 dfodd2
odd n <-> true (n % 2)
2 modlteq
n < 2 -> n % 2 = n
3 2 conv bool
bool n -> n % 2 = n
4 3 trueeqd
bool n -> (true (n % 2) <-> true n)
5 1, 4 syl5bb
bool n -> (odd n <-> true n)

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