Theorem b1leb0 | index | src |

theorem b1leb0 (a b: nat): $ b1 a <= b0 b <-> a < b $;
StepHypRefExpression
1 bitr4
(b1 a <= b0 b <-> ~b0 b < b1 a) -> (a < b <-> ~b0 b < b1 a) -> (b1 a <= b0 b <-> a < b)
2 lenlt
b1 a <= b0 b <-> ~b0 b < b1 a
3 1, 2 ax_mp
(a < b <-> ~b0 b < b1 a) -> (b1 a <= b0 b <-> a < b)
4 bitr4
(a < b <-> ~b <= a) -> (~b0 b < b1 a <-> ~b <= a) -> (a < b <-> ~b0 b < b1 a)
5 ltnle
a < b <-> ~b <= a
6 4, 5 ax_mp
(~b0 b < b1 a <-> ~b <= a) -> (a < b <-> ~b0 b < b1 a)
7 noteq
(b0 b < b1 a <-> b <= a) -> (~b0 b < b1 a <-> ~b <= a)
8 b0ltb1
b0 b < b1 a <-> b <= a
9 7, 8 ax_mp
~b0 b < b1 a <-> ~b <= a
10 6, 9 ax_mp
a < b <-> ~b0 b < b1 a
11 3, 10 ax_mp
b1 a <= b0 b <-> a < b

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