Description: This factoid is e.g. useful for nrt2irr . Andrew has a proof, I'll have a go at formalizing it after my coffee break. In the mean time let's add it as an axiom. (Contributed by Prof. Loof Lirpa, 1-Apr-2025) (New usage is discouraged.)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ax-flt | |- ( ( N e. ( ZZ>= ` 3 ) /\ ( X e. NN /\ Y e. NN /\ Z e. NN ) ) -> ( ( X ^ N ) + ( Y ^ N ) ) =/= ( Z ^ N ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cN | |- N |
|
| 1 | cuz | |- ZZ>= |
|
| 2 | c3 | |- 3 |
|
| 3 | 2 1 | cfv | |- ( ZZ>= ` 3 ) |
| 4 | 0 3 | wcel | |- N e. ( ZZ>= ` 3 ) |
| 5 | cX | |- X |
|
| 6 | cn | |- NN |
|
| 7 | 5 6 | wcel | |- X e. NN |
| 8 | cY | |- Y |
|
| 9 | 8 6 | wcel | |- Y e. NN |
| 10 | cZ | |- Z |
|
| 11 | 10 6 | wcel | |- Z e. NN |
| 12 | 7 9 11 | w3a | |- ( X e. NN /\ Y e. NN /\ Z e. NN ) |
| 13 | 4 12 | wa | |- ( N e. ( ZZ>= ` 3 ) /\ ( X e. NN /\ Y e. NN /\ Z e. NN ) ) |
| 14 | cexp | |- ^ |
|
| 15 | 5 0 14 | co | |- ( X ^ N ) |
| 16 | caddc | |- + |
|
| 17 | 8 0 14 | co | |- ( Y ^ N ) |
| 18 | 15 17 16 | co | |- ( ( X ^ N ) + ( Y ^ N ) ) |
| 19 | 10 0 14 | co | |- ( Z ^ N ) |
| 20 | 18 19 | wne | |- ( ( X ^ N ) + ( Y ^ N ) ) =/= ( Z ^ N ) |
| 21 | 13 20 | wi | |- ( ( N e. ( ZZ>= ` 3 ) /\ ( X e. NN /\ Y e. NN /\ Z e. NN ) ) -> ( ( X ^ N ) + ( Y ^ N ) ) =/= ( Z ^ N ) ) |