Lean
lemma units_eq_one (u : ℕˣ) : u = 1 := Units.ext <| Nat.eq_one_of_dvd_one ⟨u.inv, u.val_inv.symm⟩
Dedukti
2 lines
def Nat__units_eq_one : (u : Elem (Units Nat)) -> Proof (Eqt (Units Nat) u 1) := u => Units__ext Nat u 1 (Nat__eq_one_of_dvd_one (Units__val u) (existsI Nat (c => Eq 1 (times (Units__val u) c)) (Units__inv u) (Eq__symm Nat (times (Units__val u) (Units__inv u)) 1 (Units__val_inv Nat u)))).
English
Let $u$ be a unit of $\Natural$. Then $\EqtMACRoH {u}{1}$.
French
Soit $u$ une unité de $\Natural$. Alors $u$ est égal à $1$.
Czech
Nechť $u$ je jednotka $\Natural$. Tedy $\EqtMACRoH {u}{1}$.
German
Sei $u$ eine Einheit von $\Natural$. Dann $\EqtMACRoH {u}{1}$.
Swedish
Låt $u$ vara en enhet av $\Natural$. Då $\EqtMACRoH {u}{1}$.
Formula
$u \in \UnitsMACRoAX {\Natural}\vdash \EqtMACRoJ {u}{1}$
Proof
6 lines
| 1. | Let $u$ be an element of $\UnitsMACRoAX {\Natural}$. | |
| 2. | The product of the underlying value in the base of $u$ and the inverse of $u$ is equal to $1$. | Units.val_inv |
| 3. | $1$ is equal to the product of the underlying value in the base of $u$ and the inverse of $u$. | Eq.symm 2 |
| 4. | There exists an element $c$ of $\Natural$, such that $1$ is equal to the product of the underlying value in the base of $u$ and $c$. | existsI 3 |
| 5. | The underlying value in the base of $u$ is equal to $1$. | Nat.eq_one_of_dvd_one 4 |
| 6. | $\EqtMACRoJ {u}{1}$. | Units.ext 5 |
Proof, French
6 lines
| 1. | Soit $u$ un élément de $\UnitsMACRoAX {\Natural}$. | |
| 2. | Le produit du [DepNoun] sous-jacent de $u$ et de l'inverse de $u$ est égal à $1$. | Units.val_inv |
| 3. | $1$ est égal au produit du [DepNoun] sous-jacent de $u$ et de l'inverse de $u$. | Eq.symm 2 |
| 4. | Il existe un élément $c$ de $\Natural$ tel que $1$ soit égal au produit du [DepNoun] sous-jacent de $u$ et de $c$. | existsI 3 |
| 5. | Le [DepNoun] sous-jacent de $u$ est égal à $1$. | Nat.eq_one_of_dvd_one 4 |
| 6. | $\EqtMACRoJ {u}{1}$. | Units.ext 5 |
Proof, Czech
6 lines
| 1. | Nechť $u$ je prvek $\UnitsMACRoAX {\Natural}$. | |
| 2. | Součin podkladového [DepNoun] $u$ a inverze $u$ je rovný do $1$. | Units.val_inv |
| 3. | $1$ je rovné do součinu podkladového [DepNoun] $u$ a inverze $u$. | Eq.symm 2 |
| 4. | Existuje prvek $c$ $\Natural$, takový, že $1$ je rovné součinu podkladového [DepNoun] $u$ a $c$. | existsI 3 |
| 5. | Podkladový [DepNoun] $u$ je rovný $1$. | Nat.eq_one_of_dvd_one 4 |
| 6. | $\EqtMACRoJ {u}{1}$. | Units.ext 5 |
Proof, German
6 lines
| 1. | Sei $u$ ein Element von $\UnitsMACRoAX {\Natural}$. | |
| 2. | Units.val_inv | |
| 3. | Eq.symm 2 | |
| 4. | existsI 3 | |
| 5. | Nat.eq_one_of_dvd_one 4 | |
| 6. | $\EqtMACRoJ {u}{1}$. | Units.ext 5 |
Proof, Swedish
6 lines
| 1. | Låt $u$ vara ett element av $\UnitsMACRoAX {\Natural}$. | |
| 2. | $\EqtMACRoJ {\operatorname{val} (u)\times \operatorname{inv} (u)}{1}$. | Units.val_inv |
| 3. | $\EqtMACRoJ {1}{\operatorname{val} (u)\times \operatorname{inv} (u)}$. | Eq.symm 2 |
| 4. | Det finns ett element $c$ av $\Natural$, så att $1 = \operatorname{val} (u)\times c$. | existsI 3 |
| 5. | $\operatorname{val} (u)= 1$. | Nat.eq_one_of_dvd_one 4 |
| 6. | $\EqtMACRoJ {u}{1}$. | Units.ext 5 |