Metamath Proof Explorer


Theorem smoeq

Description: Equality theorem for strictly monotone functions. (Contributed by Andrew Salmon, 16-Nov-2011)

Ref Expression
Assertion smoeq ( 𝐴 = 𝐵 → ( Smo 𝐴 ↔ Smo 𝐵 ) )

Proof

Step Hyp Ref Expression
1 id ( 𝐴 = 𝐵𝐴 = 𝐵 )
2 dmeq ( 𝐴 = 𝐵 → dom 𝐴 = dom 𝐵 )
3 1 2 feq12d ( 𝐴 = 𝐵 → ( 𝐴 : dom 𝐴 ⟶ On ↔ 𝐵 : dom 𝐵 ⟶ On ) )
4 ordeq ( dom 𝐴 = dom 𝐵 → ( Ord dom 𝐴 ↔ Ord dom 𝐵 ) )
5 2 4 syl ( 𝐴 = 𝐵 → ( Ord dom 𝐴 ↔ Ord dom 𝐵 ) )
6 fveq1 ( 𝐴 = 𝐵 → ( 𝐴𝑥 ) = ( 𝐵𝑥 ) )
7 fveq1 ( 𝐴 = 𝐵 → ( 𝐴𝑦 ) = ( 𝐵𝑦 ) )
8 6 7 eleq12d ( 𝐴 = 𝐵 → ( ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ↔ ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) )
9 8 imbi2d ( 𝐴 = 𝐵 → ( ( 𝑥𝑦 → ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ) ↔ ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
10 9 2ralbidv ( 𝐴 = 𝐵 → ( ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ) ↔ ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
11 2 raleqdv ( 𝐴 = 𝐵 → ( ∀ 𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ↔ ∀ 𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
12 11 ralbidv ( 𝐴 = 𝐵 → ( ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ↔ ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
13 2 raleqdv ( 𝐴 = 𝐵 → ( ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ↔ ∀ 𝑥 ∈ dom 𝐵𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
14 10 12 13 3bitrd ( 𝐴 = 𝐵 → ( ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ) ↔ ∀ 𝑥 ∈ dom 𝐵𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
15 3 5 14 3anbi123d ( 𝐴 = 𝐵 → ( ( 𝐴 : dom 𝐴 ⟶ On ∧ Ord dom 𝐴 ∧ ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ) ) ↔ ( 𝐵 : dom 𝐵 ⟶ On ∧ Ord dom 𝐵 ∧ ∀ 𝑥 ∈ dom 𝐵𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) ) )
16 df-smo ( Smo 𝐴 ↔ ( 𝐴 : dom 𝐴 ⟶ On ∧ Ord dom 𝐴 ∧ ∀ 𝑥 ∈ dom 𝐴𝑦 ∈ dom 𝐴 ( 𝑥𝑦 → ( 𝐴𝑥 ) ∈ ( 𝐴𝑦 ) ) ) )
17 df-smo ( Smo 𝐵 ↔ ( 𝐵 : dom 𝐵 ⟶ On ∧ Ord dom 𝐵 ∧ ∀ 𝑥 ∈ dom 𝐵𝑦 ∈ dom 𝐵 ( 𝑥𝑦 → ( 𝐵𝑥 ) ∈ ( 𝐵𝑦 ) ) ) )
18 15 16 17 3bitr4g ( 𝐴 = 𝐵 → ( Smo 𝐴 ↔ Smo 𝐵 ) )