Metamath Proof Explorer


Theorem 5m1e4

Description: 5 - 1 = 4. (Contributed by AV, 6-Sep-2021)

Ref Expression
Assertion 5m1e4 51=4

Proof

Step Hyp Ref Expression
1 4cn 4
2 ax-1cn 1
3 df-5 5=4+1
4 1 2 3 mvrraddi 51=4