Metamath Proof Explorer

Theorem 4m1e3

Description: 4 - 1 = 3. (Contributed by AV, 8-Feb-2021) (Proof shortened by AV, 6-Sep-2021)

Ref Expression
Assertion 4m1e3 
|- ( 4 - 1 ) = 3

Proof

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