Metamath Proof Explorer


Theorem 7m1e6

Description: 7 - 1 = 6. (Contributed by AV, 6-Sep-2021)

Ref Expression
Assertion 7m1e6
|- ( 7 - 1 ) = 6

Proof

Step Hyp Ref Expression
1 6cn
 |-  6 e. CC
2 ax-1cn
 |-  1 e. CC
3 df-7
 |-  7 = ( 6 + 1 )
4 1 2 3 mvrraddi
 |-  ( 7 - 1 ) = 6