Theorem zlt0sub | index | src |

theorem zlt0sub (a b: nat): $ 0  b 
    
StepHypRefExpression
1 bitr3
(0 +Z b <Z a <-> 0 <Z a -Z b) -> (0 +Z b <Z a <-> b <Z a) -> (0 <Z a -Z b <-> b <Z a)
2 zltaddsub
0 +Z b <Z a <-> 0 <Z a -Z b
3 1, 2 ax_mp
(0 +Z b <Z a <-> b <Z a) -> (0 <Z a -Z b <-> b <Z a)
4 zlteq1
0 +Z b = b -> (0 +Z b <Z a <-> b <Z a)
5 zadd01
0 +Z b = b
6 4, 5 ax_mp
0 +Z b <Z a <-> b <Z a
7 3, 6 ax_mp
0 <Z a -Z b <-> b <Z a

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)