Metamath Proof Explorer


Definition df-oexp

Description: Define the ordinal exponentiation operation. (Contributed by NM, 30-Dec-2004)

Ref Expression
Assertion df-oexp o = ( 𝑥 ∈ On , 𝑦 ∈ On ↦ if ( 𝑥 = ∅ , ( 1o𝑦 ) , ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o ) ‘ 𝑦 ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 coe o
1 vx 𝑥
2 con0 On
3 vy 𝑦
4 1 cv 𝑥
5 c0
6 4 5 wceq 𝑥 = ∅
7 c1o 1o
8 3 cv 𝑦
9 7 8 cdif ( 1o𝑦 )
10 vz 𝑧
11 cvv V
12 10 cv 𝑧
13 comu ·o
14 12 4 13 co ( 𝑧 ·o 𝑥 )
15 10 11 14 cmpt ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) )
16 15 7 crdg rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o )
17 8 16 cfv ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o ) ‘ 𝑦 )
18 6 9 17 cif if ( 𝑥 = ∅ , ( 1o𝑦 ) , ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o ) ‘ 𝑦 ) )
19 1 3 2 2 18 cmpo ( 𝑥 ∈ On , 𝑦 ∈ On ↦ if ( 𝑥 = ∅ , ( 1o𝑦 ) , ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o ) ‘ 𝑦 ) ) )
20 0 19 wceq o = ( 𝑥 ∈ On , 𝑦 ∈ On ↦ if ( 𝑥 = ∅ , ( 1o𝑦 ) , ( rec ( ( 𝑧 ∈ V ↦ ( 𝑧 ·o 𝑥 ) ) , 1o ) ‘ 𝑦 ) ) )