Theorem zsubpos ≪ | index | src | ≫ 

theorem zsubpos (m n: nat): $ n <= m -> b0 m -Z b0 n = b0 (m - n) $;
StepHypRefExpression
1 zsubb0 
b0 m -Z b0 n = m -ZN n
2 znsubpos 
n <= m -> m -ZN n = b0 (m - n)
3 1, 2 syl5eq 
n <= m -> b0 m -Z b0 n = b0 (m - 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, the0), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)