Metamath Proof Explorer


Theorem cantnfrescl

Description: A function is finitely supported from B to A iff the extended function is finitely supported from D to A . (Contributed by Mario Carneiro, 25-May-2015)

Ref Expression
Hypotheses cantnfs.s 𝑆 = dom ( 𝐴 CNF 𝐵 )
cantnfs.a ( 𝜑𝐴 ∈ On )
cantnfs.b ( 𝜑𝐵 ∈ On )
cantnfrescl.d ( 𝜑𝐷 ∈ On )
cantnfrescl.b ( 𝜑𝐵𝐷 )
cantnfrescl.x ( ( 𝜑𝑛 ∈ ( 𝐷𝐵 ) ) → 𝑋 = ∅ )
cantnfrescl.a ( 𝜑 → ∅ ∈ 𝐴 )
cantnfrescl.t 𝑇 = dom ( 𝐴 CNF 𝐷 )
Assertion cantnfrescl ( 𝜑 → ( ( 𝑛𝐵𝑋 ) ∈ 𝑆 ↔ ( 𝑛𝐷𝑋 ) ∈ 𝑇 ) )

Proof

Step Hyp Ref Expression
1 cantnfs.s 𝑆 = dom ( 𝐴 CNF 𝐵 )
2 cantnfs.a ( 𝜑𝐴 ∈ On )
3 cantnfs.b ( 𝜑𝐵 ∈ On )
4 cantnfrescl.d ( 𝜑𝐷 ∈ On )
5 cantnfrescl.b ( 𝜑𝐵𝐷 )
6 cantnfrescl.x ( ( 𝜑𝑛 ∈ ( 𝐷𝐵 ) ) → 𝑋 = ∅ )
7 cantnfrescl.a ( 𝜑 → ∅ ∈ 𝐴 )
8 cantnfrescl.t 𝑇 = dom ( 𝐴 CNF 𝐷 )
9 7 adantr ( ( 𝜑𝑛 ∈ ( 𝐷𝐵 ) ) → ∅ ∈ 𝐴 )
10 6 9 eqeltrd ( ( 𝜑𝑛 ∈ ( 𝐷𝐵 ) ) → 𝑋𝐴 )
11 10 ralrimiva ( 𝜑 → ∀ 𝑛 ∈ ( 𝐷𝐵 ) 𝑋𝐴 )
12 5 11 raldifeq ( 𝜑 → ( ∀ 𝑛𝐵 𝑋𝐴 ↔ ∀ 𝑛𝐷 𝑋𝐴 ) )
13 eqid ( 𝑛𝐵𝑋 ) = ( 𝑛𝐵𝑋 )
14 13 fmpt ( ∀ 𝑛𝐵 𝑋𝐴 ↔ ( 𝑛𝐵𝑋 ) : 𝐵𝐴 )
15 eqid ( 𝑛𝐷𝑋 ) = ( 𝑛𝐷𝑋 )
16 15 fmpt ( ∀ 𝑛𝐷 𝑋𝐴 ↔ ( 𝑛𝐷𝑋 ) : 𝐷𝐴 )
17 12 14 16 3bitr3g ( 𝜑 → ( ( 𝑛𝐵𝑋 ) : 𝐵𝐴 ↔ ( 𝑛𝐷𝑋 ) : 𝐷𝐴 ) )
18 3 mptexd ( 𝜑 → ( 𝑛𝐵𝑋 ) ∈ V )
19 funmpt Fun ( 𝑛𝐵𝑋 )
20 19 a1i ( 𝜑 → Fun ( 𝑛𝐵𝑋 ) )
21 4 mptexd ( 𝜑 → ( 𝑛𝐷𝑋 ) ∈ V )
22 funmpt Fun ( 𝑛𝐷𝑋 )
23 21 22 jctir ( 𝜑 → ( ( 𝑛𝐷𝑋 ) ∈ V ∧ Fun ( 𝑛𝐷𝑋 ) ) )
24 18 20 23 jca31 ( 𝜑 → ( ( ( 𝑛𝐵𝑋 ) ∈ V ∧ Fun ( 𝑛𝐵𝑋 ) ) ∧ ( ( 𝑛𝐷𝑋 ) ∈ V ∧ Fun ( 𝑛𝐷𝑋 ) ) ) )
25 4 5 6 extmptsuppeq ( 𝜑 → ( ( 𝑛𝐵𝑋 ) supp ∅ ) = ( ( 𝑛𝐷𝑋 ) supp ∅ ) )
26 suppeqfsuppbi ( ( ( ( 𝑛𝐵𝑋 ) ∈ V ∧ Fun ( 𝑛𝐵𝑋 ) ) ∧ ( ( 𝑛𝐷𝑋 ) ∈ V ∧ Fun ( 𝑛𝐷𝑋 ) ) ) → ( ( ( 𝑛𝐵𝑋 ) supp ∅ ) = ( ( 𝑛𝐷𝑋 ) supp ∅ ) → ( ( 𝑛𝐵𝑋 ) finSupp ∅ ↔ ( 𝑛𝐷𝑋 ) finSupp ∅ ) ) )
27 24 25 26 sylc ( 𝜑 → ( ( 𝑛𝐵𝑋 ) finSupp ∅ ↔ ( 𝑛𝐷𝑋 ) finSupp ∅ ) )
28 17 27 anbi12d ( 𝜑 → ( ( ( 𝑛𝐵𝑋 ) : 𝐵𝐴 ∧ ( 𝑛𝐵𝑋 ) finSupp ∅ ) ↔ ( ( 𝑛𝐷𝑋 ) : 𝐷𝐴 ∧ ( 𝑛𝐷𝑋 ) finSupp ∅ ) ) )
29 1 2 3 cantnfs ( 𝜑 → ( ( 𝑛𝐵𝑋 ) ∈ 𝑆 ↔ ( ( 𝑛𝐵𝑋 ) : 𝐵𝐴 ∧ ( 𝑛𝐵𝑋 ) finSupp ∅ ) ) )
30 8 2 4 cantnfs ( 𝜑 → ( ( 𝑛𝐷𝑋 ) ∈ 𝑇 ↔ ( ( 𝑛𝐷𝑋 ) : 𝐷𝐴 ∧ ( 𝑛𝐷𝑋 ) finSupp ∅ ) ) )
31 28 29 30 3bitr4d ( 𝜑 → ( ( 𝑛𝐵𝑋 ) ∈ 𝑆 ↔ ( 𝑛𝐷𝑋 ) ∈ 𝑇 ) )