Metamath Proof Explorer


Definition df-omul

Description: Define the ordinal multiplication operation. (Contributed by NM, 26-Aug-1995)

Ref Expression
Assertion df-omul ·o = ( 𝑥 ∈ On , 𝑦 ∈ On ↦ ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) ) , ∅ ) ‘ 𝑦 ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 comu ⊢ ·o
1 vx ⊢ 𝑥
2 con0 ⊢ On
3 vy ⊢ 𝑦
4 vz ⊢ 𝑧
5 cvv ⊢ V
6 4 cv ⊢ 𝑧
7 coa ⊢ +o
8 1 cv ⊢ 𝑥
9 6 8 7 co ⊢ ( 𝑧 +o 𝑥 )
10 4 5 9 cmpt ⊢ ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) )
11 c0 ⊢ ∅
12 10 11 crdg ⊢ rec ( ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) ) , ∅ )
13 3 cv ⊢ 𝑦
14 13 12 cfv ⊢ ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) ) , ∅ ) ‘ 𝑦 )
15 1 3 2 2 14 cmpo ⊢ ( 𝑥 ∈ On , 𝑦 ∈ On ↦ ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) ) , ∅ ) ‘ 𝑦 ) )
16 0 15 wceq ⊢ ·o = ( 𝑥 ∈ On , 𝑦 ∈ On ↦ ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 +o 𝑥 ) ) , ∅ ) ‘ 𝑦 ) )