Metamath Proof Explorer


Theorem 9p5e14

Description: 9 + 5 = 14. (Contributed by Mario Carneiro, 19-Apr-2015)

Ref Expression
Assertion 9p5e14 ( 9 + 5 ) = 1 4

Proof

Step Hyp Ref Expression
1 9nn0 9 ∈ ℕ0
2 4nn0 4 ∈ ℕ0
3 3nn0 3 ∈ ℕ0
4 df-5 5 = ( 4 + 1 )
5 df-4 4 = ( 3 + 1 )
6 9p4e13 ( 9 + 4 ) = 1 3
7 1 2 3 4 5 6 6p5lem ( 9 + 5 ) = 1 4