Metamath Proof Explorer


Theorem 4bc3eq4

Description: The value of four choose three. (Contributed by Scott Fenton, 11-Jun-2016)

Ref Expression
Assertion 4bc3eq4 ⊢ ( 4 3 ) = 4

Proof

Step Hyp Ref Expression
1 4m1e3 ⊢ 4 − 1 = 3
2 1 oveq2i ⊢ ( 4 4 − 1 ) = ( 4 3 )
3 4nn0 ⊢ 4 ∈ ℕ 0
4 bcnm1 ⊢ 4 ∈ ℕ 0 → ( 4 4 − 1 ) = 4
5 3 4 ax-mp ⊢ ( 4 4 − 1 ) = 4
6 2 5 eqtr3i ⊢ ( 4 3 ) = 4