diff --git a/Game/Levels/AdvMultiplication/L03eq_succ_of_ne_zero.lean b/Game/Levels/AdvMultiplication/L03eq_succ_of_ne_zero.lean index 4328783..7854468 100644 --- a/Game/Levels/AdvMultiplication/L03eq_succ_of_ne_zero.lean +++ b/Game/Levels/AdvMultiplication/L03eq_succ_of_ne_zero.lean @@ -50,7 +50,7 @@ TheoremDoc MyNat.eq_succ_of_ne_zero as "eq_succ_of_ne_zero" in "≤" Introduction "Multiplication usually makes a number bigger, but multiplication by zero can make it smaller. Thus many lemmas about inequalities and multiplication need the -hypothesis `a ≠ 0`. Here is a key lemma enables us to use this hypothesis. +hypothesis `a ≠ 0`. Here is a key lemma that enables us to use this hypothesis. To help us with the proof, we can use the `tauto` tactic. Click on the tactic's name on the right to see what it does. " diff --git a/Game/Levels/AdvMultiplication/L05le_mul_right.lean b/Game/Levels/AdvMultiplication/L05le_mul_right.lean index 8540e23..d22d88b 100644 --- a/Game/Levels/AdvMultiplication/L05le_mul_right.lean +++ b/Game/Levels/AdvMultiplication/L05le_mul_right.lean @@ -19,7 +19,7 @@ TheoremDoc MyNat.le_mul_right as "le_mul_right" in "≤" Introduction " In Prime Number World we will be proving that $2$ is prime. -To do this, we will have to rule out things like $2 ≠ 37 × 42.$ +To do this, we will have to rule out things like $2 = 37 × 42.$ We will do this by proving that any factor of $2$ is at most $2$, which we will do using this lemma. The proof I have in mind manipulates the hypothesis until it becomes the goal, using pretty much everything which we've proved in this world so far. diff --git a/Game/Levels/AdvMultiplication/L06mul_right_eq_one.lean b/Game/Levels/AdvMultiplication/L06mul_right_eq_one.lean index 6f39832..207788c 100644 --- a/Game/Levels/AdvMultiplication/L06mul_right_eq_one.lean +++ b/Game/Levels/AdvMultiplication/L06mul_right_eq_one.lean @@ -38,7 +38,7 @@ to the context, because you just supplied the proof of it (`succ_inj a b`). ## Example If you have a proof to hand, then you don't even need to state what you -are proving. example +are proving. For example `have h2 := succ_inj a b`