Theorem zleznsub0 | index | src |

theorem zleznsub0 (a b: nat): $ a -ZN b <=Z 0 <-> a <= b $;
StepHypRefExpression
1 bitr4
(a -ZN b <=Z 0 <-> ~b < a) -> (a <= b <-> ~b < a) -> (a -ZN b <=Z 0 <-> a <= b)
2 noteq
(0 <Z a -ZN b <-> b < a) -> (~0 <Z a -ZN b <-> ~b < a)
3 2 conv zle
(0 <Z a -ZN b <-> b < a) -> (a -ZN b <=Z 0 <-> ~b < a)
4 zlt0znsub
0 <Z a -ZN b <-> b < a
5 3, 4 ax_mp
a -ZN b <=Z 0 <-> ~b < a
6 1, 5 ax_mp
(a <= b <-> ~b < a) -> (a -ZN b <=Z 0 <-> a <= b)
7 lenlt
a <= b <-> ~b < a
8 6, 7 ax_mp
a -ZN b <=Z 0 <-> 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_set (elab, ax_8), axs_the (theid, the0), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)