Metamath Proof Explorer
Description: A "decimal digit" (i.e. a nonnegative integer less than or equal to 9)
is less then 10. (Contributed by AV, 8-Sep-2021)
|
|
Ref |
Expression |
|
Hypotheses |
le9lt10.c |
⊢ 𝐴 ∈ ℕ0 |
|
|
le9lt10.e |
⊢ 𝐴 ≤ 9 |
|
Assertion |
le9lt10 |
⊢ 𝐴 < ; 1 0 |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
le9lt10.c |
⊢ 𝐴 ∈ ℕ0 |
2 |
|
le9lt10.e |
⊢ 𝐴 ≤ 9 |
3 |
1
|
nn0zi |
⊢ 𝐴 ∈ ℤ |
4 |
|
9nn0 |
⊢ 9 ∈ ℕ0 |
5 |
4
|
nn0zi |
⊢ 9 ∈ ℤ |
6 |
|
zleltp1 |
⊢ ( ( 𝐴 ∈ ℤ ∧ 9 ∈ ℤ ) → ( 𝐴 ≤ 9 ↔ 𝐴 < ( 9 + 1 ) ) ) |
7 |
3 5 6
|
mp2an |
⊢ ( 𝐴 ≤ 9 ↔ 𝐴 < ( 9 + 1 ) ) |
8 |
2 7
|
mpbi |
⊢ 𝐴 < ( 9 + 1 ) |
9 |
|
9p1e10 |
⊢ ( 9 + 1 ) = ; 1 0 |
10 |
8 9
|
breqtri |
⊢ 𝐴 < ; 1 0 |