Metamath Proof Explorer


Theorem 3p4e7

Description: 3 + 4 = 7. (Contributed by SN, 24-Aug-2026)

Ref Expression
Assertion 3p4e7 3 + 4 = 7

Proof

Step Hyp Ref Expression
1 3cn 3
2 2cn 2
3 1 2 2 addassi 3 + 2 + 2 = 3 + 2 + 2
4 3p2e5 3 + 2 = 5
5 4 oveq1i 3 + 2 + 2 = 5 + 2
6 5p2e7 5 + 2 = 7
7 5 6 eqtri 3 + 2 + 2 = 7
8 2p2e4 2 + 2 = 4
9 8 oveq2i 3 + 2 + 2 = 3 + 4
10 3 7 9 3eqtr3ri 3 + 4 = 7