Metamath Proof Explorer


Theorem mapdom3

Description: Set exponentiation dominates the base. (Contributed by Mario Carneiro, 30-Apr-2015) (Proof shortened by AV, 17-Jul-2022)

Ref Expression
Assertion mapdom3 ( ( 𝐴𝑉𝐵𝑊𝐵 ≠ ∅ ) → 𝐴 ≼ ( 𝐴m 𝐵 ) )

Proof

Step Hyp Ref Expression
1 n0 ( 𝐵 ≠ ∅ ↔ ∃ 𝑥 𝑥𝐵 )
2 simp1 ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → 𝐴𝑉 )
3 simp3 ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → 𝑥𝐵 )
4 2 3 mapsnend ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → ( 𝐴m { 𝑥 } ) ≈ 𝐴 )
5 4 ensymd ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → 𝐴 ≈ ( 𝐴m { 𝑥 } ) )
6 simp2 ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → 𝐵𝑊 )
7 3 snssd ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → { 𝑥 } ⊆ 𝐵 )
8 ssdomg ( 𝐵𝑊 → ( { 𝑥 } ⊆ 𝐵 → { 𝑥 } ≼ 𝐵 ) )
9 6 7 8 sylc ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → { 𝑥 } ≼ 𝐵 )
10 vex 𝑥 ∈ V
11 10 snnz { 𝑥 } ≠ ∅
12 simpl ( ( { 𝑥 } = ∅ ∧ 𝐴 = ∅ ) → { 𝑥 } = ∅ )
13 12 necon3ai ( { 𝑥 } ≠ ∅ → ¬ ( { 𝑥 } = ∅ ∧ 𝐴 = ∅ ) )
14 11 13 ax-mp ¬ ( { 𝑥 } = ∅ ∧ 𝐴 = ∅ )
15 mapdom2 ( ( { 𝑥 } ≼ 𝐵 ∧ ¬ ( { 𝑥 } = ∅ ∧ 𝐴 = ∅ ) ) → ( 𝐴m { 𝑥 } ) ≼ ( 𝐴m 𝐵 ) )
16 9 14 15 sylancl ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → ( 𝐴m { 𝑥 } ) ≼ ( 𝐴m 𝐵 ) )
17 endomtr ( ( 𝐴 ≈ ( 𝐴m { 𝑥 } ) ∧ ( 𝐴m { 𝑥 } ) ≼ ( 𝐴m 𝐵 ) ) → 𝐴 ≼ ( 𝐴m 𝐵 ) )
18 5 16 17 syl2anc ( ( 𝐴𝑉𝐵𝑊𝑥𝐵 ) → 𝐴 ≼ ( 𝐴m 𝐵 ) )
19 18 3expia ( ( 𝐴𝑉𝐵𝑊 ) → ( 𝑥𝐵𝐴 ≼ ( 𝐴m 𝐵 ) ) )
20 19 exlimdv ( ( 𝐴𝑉𝐵𝑊 ) → ( ∃ 𝑥 𝑥𝐵𝐴 ≼ ( 𝐴m 𝐵 ) ) )
21 1 20 syl5bi ( ( 𝐴𝑉𝐵𝑊 ) → ( 𝐵 ≠ ∅ → 𝐴 ≼ ( 𝐴m 𝐵 ) ) )
22 21 3impia ( ( 𝐴𝑉𝐵𝑊𝐵 ≠ ∅ ) → 𝐴 ≼ ( 𝐴m 𝐵 ) )