Metamath Proof Explorer


Theorem 5m1e4

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

Ref Expression
Assertion 5m1e4
|- ( 5 - 1 ) = 4

Proof

Step Hyp Ref Expression
1 4cn
 |-  4 e. CC
2 ax-1cn
 |-  1 e. CC
3 df-5
 |-  5 = ( 4 + 1 )
4 1 2 3 mvrraddi
 |-  ( 5 - 1 ) = 4