Metamath Proof Explorer


Theorem matbas2i

Description: A matrix is a function. (Contributed by Stefan O'Rear, 11-Sep-2015)

Ref Expression
Hypotheses matbas2.a 𝐴 = ( 𝑁 Mat 𝑅 )
matbas2.k 𝐾 = ( Base ‘ 𝑅 )
matbas2i.b 𝐵 = ( Base ‘ 𝐴 )
Assertion matbas2i ( 𝑀𝐵𝑀 ∈ ( 𝐾m ( 𝑁 × 𝑁 ) ) )

Proof

Step Hyp Ref Expression
1 matbas2.a 𝐴 = ( 𝑁 Mat 𝑅 )
2 matbas2.k 𝐾 = ( Base ‘ 𝑅 )
3 matbas2i.b 𝐵 = ( Base ‘ 𝐴 )
4 id ( 𝑀𝐵𝑀𝐵 )
5 4 3 eleqtrdi ( 𝑀𝐵𝑀 ∈ ( Base ‘ 𝐴 ) )
6 1 3 matrcl ( 𝑀𝐵 → ( 𝑁 ∈ Fin ∧ 𝑅 ∈ V ) )
7 1 2 matbas2 ( ( 𝑁 ∈ Fin ∧ 𝑅 ∈ V ) → ( 𝐾m ( 𝑁 × 𝑁 ) ) = ( Base ‘ 𝐴 ) )
8 6 7 syl ( 𝑀𝐵 → ( 𝐾m ( 𝑁 × 𝑁 ) ) = ( Base ‘ 𝐴 ) )
9 5 8 eleqtrrd ( 𝑀𝐵𝑀 ∈ ( 𝐾m ( 𝑁 × 𝑁 ) ) )