Theorem shl2dvd | index | src |

theorem shl2dvd (a b: nat): $ 0 < b -> 2 || shl a b $;
StepHypRefExpression
1 powdvd1
0 < b -> 2 || 2 ^ b
2 shlpow2dvd
2 ^ b || shl a b
3 dvdtr
2 || 2 ^ b -> 2 ^ b || shl a b -> 2 || shl a b
4 2, 3 mpi
2 || 2 ^ b -> 2 || shl a b
5 1, 4 rsyl
0 < b -> 2 || shl 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)