Description: 7 + 6 = 13. (Contributed by Mario Carneiro, 19-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | 7p6e13 | ⊢ ( 7 + 6 ) = ; 1 3 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 7nn0 | ⊢ 7 ∈ ℕ_{0} | |
2 | 5nn0 | ⊢ 5 ∈ ℕ_{0} | |
3 | 2nn0 | ⊢ 2 ∈ ℕ_{0} | |
4 | df-6 | ⊢ 6 = ( 5 + 1 ) | |
5 | df-3 | ⊢ 3 = ( 2 + 1 ) | |
6 | 7p5e12 | ⊢ ( 7 + 5 ) = ; 1 2 | |
7 | 1 2 3 4 5 6 | 6p5lem | ⊢ ( 7 + 6 ) = ; 1 3 |