Metamath Proof Explorer


Theorem mapsnf1o3

Description: Explicit bijection in the reverse of mapsnf1o2 . (Contributed by Stefan O'Rear, 24-Mar-2015)

Ref Expression
Hypotheses mapsncnv.s 𝑆 = { 𝑋 }
mapsncnv.b 𝐵 ∈ V
mapsncnv.x 𝑋 ∈ V
mapsnf1o3.f 𝐹 = ( 𝑦𝐵 ↦ ( 𝑆 × { 𝑦 } ) )
Assertion mapsnf1o3 𝐹 : 𝐵1-1-onto→ ( 𝐵m 𝑆 )

Proof

Step Hyp Ref Expression
1 mapsncnv.s 𝑆 = { 𝑋 }
2 mapsncnv.b 𝐵 ∈ V
3 mapsncnv.x 𝑋 ∈ V
4 mapsnf1o3.f 𝐹 = ( 𝑦𝐵 ↦ ( 𝑆 × { 𝑦 } ) )
5 eqid ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) = ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) )
6 1 2 3 5 mapsnf1o2 ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : ( 𝐵m 𝑆 ) –1-1-onto𝐵
7 f1ocnv ( ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : ( 𝐵m 𝑆 ) –1-1-onto𝐵 ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : 𝐵1-1-onto→ ( 𝐵m 𝑆 ) )
8 6 7 ax-mp ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : 𝐵1-1-onto→ ( 𝐵m 𝑆 )
9 1 2 3 5 mapsncnv ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) = ( 𝑦𝐵 ↦ ( 𝑆 × { 𝑦 } ) )
10 4 9 eqtr4i 𝐹 = ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) )
11 f1oeq1 ( 𝐹 = ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) → ( 𝐹 : 𝐵1-1-onto→ ( 𝐵m 𝑆 ) ↔ ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : 𝐵1-1-onto→ ( 𝐵m 𝑆 ) ) )
12 10 11 ax-mp ( 𝐹 : 𝐵1-1-onto→ ( 𝐵m 𝑆 ) ↔ ( 𝑥 ∈ ( 𝐵m 𝑆 ) ↦ ( 𝑥𝑋 ) ) : 𝐵1-1-onto→ ( 𝐵m 𝑆 ) )
13 8 12 mpbir 𝐹 : 𝐵1-1-onto→ ( 𝐵m 𝑆 )