Metamath Proof Explorer


Theorem ismnt

Description: Express the statement " F is monotone". (Contributed by Thierry Arnoux, 23-Apr-2024)

Ref Expression
Hypotheses mntoval.1 𝐴 = ( Base ‘ 𝑉 )
mntoval.2 𝐵 = ( Base ‘ 𝑊 )
mntoval.3 = ( le ‘ 𝑉 )
mntoval.4 = ( le ‘ 𝑊 )
Assertion ismnt ( ( 𝑉𝑋𝑊𝑌 ) → ( 𝐹 ∈ ( 𝑉 Monot 𝑊 ) ↔ ( 𝐹 : 𝐴𝐵 ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) ) )

Proof

Step Hyp Ref Expression
1 mntoval.1 𝐴 = ( Base ‘ 𝑉 )
2 mntoval.2 𝐵 = ( Base ‘ 𝑊 )
3 mntoval.3 = ( le ‘ 𝑉 )
4 mntoval.4 = ( le ‘ 𝑊 )
5 1 2 3 4 mntoval ( ( 𝑉𝑋𝑊𝑌 ) → ( 𝑉 Monot 𝑊 ) = { 𝑓 ∈ ( 𝐵m 𝐴 ) ∣ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝑓𝑥 ) ( 𝑓𝑦 ) ) } )
6 5 eleq2d ( ( 𝑉𝑋𝑊𝑌 ) → ( 𝐹 ∈ ( 𝑉 Monot 𝑊 ) ↔ 𝐹 ∈ { 𝑓 ∈ ( 𝐵m 𝐴 ) ∣ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝑓𝑥 ) ( 𝑓𝑦 ) ) } ) )
7 fveq1 ( 𝑓 = 𝐹 → ( 𝑓𝑥 ) = ( 𝐹𝑥 ) )
8 fveq1 ( 𝑓 = 𝐹 → ( 𝑓𝑦 ) = ( 𝐹𝑦 ) )
9 7 8 breq12d ( 𝑓 = 𝐹 → ( ( 𝑓𝑥 ) ( 𝑓𝑦 ) ↔ ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) )
10 9 imbi2d ( 𝑓 = 𝐹 → ( ( 𝑥 𝑦 → ( 𝑓𝑥 ) ( 𝑓𝑦 ) ) ↔ ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) )
11 10 2ralbidv ( 𝑓 = 𝐹 → ( ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝑓𝑥 ) ( 𝑓𝑦 ) ) ↔ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) )
12 11 elrab ( 𝐹 ∈ { 𝑓 ∈ ( 𝐵m 𝐴 ) ∣ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝑓𝑥 ) ( 𝑓𝑦 ) ) } ↔ ( 𝐹 ∈ ( 𝐵m 𝐴 ) ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) )
13 6 12 bitrdi ( ( 𝑉𝑋𝑊𝑌 ) → ( 𝐹 ∈ ( 𝑉 Monot 𝑊 ) ↔ ( 𝐹 ∈ ( 𝐵m 𝐴 ) ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) ) )
14 2 fvexi 𝐵 ∈ V
15 1 fvexi 𝐴 ∈ V
16 14 15 elmap ( 𝐹 ∈ ( 𝐵m 𝐴 ) ↔ 𝐹 : 𝐴𝐵 )
17 16 anbi1i ( ( 𝐹 ∈ ( 𝐵m 𝐴 ) ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) ↔ ( 𝐹 : 𝐴𝐵 ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) )
18 13 17 bitrdi ( ( 𝑉𝑋𝑊𝑌 ) → ( 𝐹 ∈ ( 𝑉 Monot 𝑊 ) ↔ ( 𝐹 : 𝐴𝐵 ∧ ∀ 𝑥𝐴𝑦𝐴 ( 𝑥 𝑦 → ( 𝐹𝑥 ) ( 𝐹𝑦 ) ) ) ) )