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Metamath Proof Explorer

Theorem 2t2e4

Description: 2 times 2 equals 4. (Contributed by NM, 1-Aug-1999)

Ref Expression
Assertion 2t2e4 ( 2 · 2 ) = 4

Proof

Step Hyp Ref Expression
1 2cn ⊢ 2 ∈ ℂ
2 1 2timesi ⊢ ( 2 · 2 ) = ( 2 + 2 )
3 2p2e4 ⊢ ( 2 + 2 ) = 4
4 2 3 eqtri ⊢ ( 2 · 2 ) = 4