Metamath Proof Explorer


Theorem f1imadifssran

Description: Condition for the range of a one-to-one function to be the range of one its restrictions. Variant of imadifssran . (Contributed by AV, 4-Oct-2025)

Ref Expression
Assertion f1imadifssran ( Fun 𝐹 → ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ran ( 𝐹𝐴 ) → ran 𝐹 = ran ( 𝐹𝐴 ) ) )

Proof

Step Hyp Ref Expression
1 imadmrn ( 𝐹 “ dom 𝐹 ) = ran 𝐹
2 imadif ( Fun 𝐹 → ( 𝐹 “ ( dom 𝐹𝐴 ) ) = ( ( 𝐹 “ dom 𝐹 ) ∖ ( 𝐹𝐴 ) ) )
3 2 sseq1d ( Fun 𝐹 → ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) ↔ ( ( 𝐹 “ dom 𝐹 ) ∖ ( 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) ) )
4 ssundif ( ( 𝐹 “ dom 𝐹 ) ⊆ ( ( 𝐹𝐴 ) ∪ ( 𝐹𝐴 ) ) ↔ ( ( 𝐹 “ dom 𝐹 ) ∖ ( 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) )
5 unidm ( ( 𝐹𝐴 ) ∪ ( 𝐹𝐴 ) ) = ( 𝐹𝐴 )
6 5 sseq2i ( ( 𝐹 “ dom 𝐹 ) ⊆ ( ( 𝐹𝐴 ) ∪ ( 𝐹𝐴 ) ) ↔ ( 𝐹 “ dom 𝐹 ) ⊆ ( 𝐹𝐴 ) )
7 id ( ( 𝐹 “ dom 𝐹 ) ⊆ ( 𝐹𝐴 ) → ( 𝐹 “ dom 𝐹 ) ⊆ ( 𝐹𝐴 ) )
8 imassrn ( 𝐹𝐴 ) ⊆ ran 𝐹
9 8 1 sseqtrri ( 𝐹𝐴 ) ⊆ ( 𝐹 “ dom 𝐹 )
10 9 a1i ( ( 𝐹 “ dom 𝐹 ) ⊆ ( 𝐹𝐴 ) → ( 𝐹𝐴 ) ⊆ ( 𝐹 “ dom 𝐹 ) )
11 7 10 eqssd ( ( 𝐹 “ dom 𝐹 ) ⊆ ( 𝐹𝐴 ) → ( 𝐹 “ dom 𝐹 ) = ( 𝐹𝐴 ) )
12 6 11 sylbi ( ( 𝐹 “ dom 𝐹 ) ⊆ ( ( 𝐹𝐴 ) ∪ ( 𝐹𝐴 ) ) → ( 𝐹 “ dom 𝐹 ) = ( 𝐹𝐴 ) )
13 4 12 sylbir ( ( ( 𝐹 “ dom 𝐹 ) ∖ ( 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) → ( 𝐹 “ dom 𝐹 ) = ( 𝐹𝐴 ) )
14 3 13 biimtrdi ( Fun 𝐹 → ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) → ( 𝐹 “ dom 𝐹 ) = ( 𝐹𝐴 ) ) )
15 14 imp ( ( Fun 𝐹 ∧ ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) ) → ( 𝐹 “ dom 𝐹 ) = ( 𝐹𝐴 ) )
16 1 15 eqtr3id ( ( Fun 𝐹 ∧ ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) ) → ran 𝐹 = ( 𝐹𝐴 ) )
17 16 ex ( Fun 𝐹 → ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) → ran 𝐹 = ( 𝐹𝐴 ) ) )
18 df-ima ( 𝐹𝐴 ) = ran ( 𝐹𝐴 )
19 18 eqcomi ran ( 𝐹𝐴 ) = ( 𝐹𝐴 )
20 19 sseq2i ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ran ( 𝐹𝐴 ) ↔ ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ( 𝐹𝐴 ) )
21 19 eqeq2i ( ran 𝐹 = ran ( 𝐹𝐴 ) ↔ ran 𝐹 = ( 𝐹𝐴 ) )
22 17 20 21 3imtr4g ( Fun 𝐹 → ( ( 𝐹 “ ( dom 𝐹𝐴 ) ) ⊆ ran ( 𝐹𝐴 ) → ran 𝐹 = ran ( 𝐹𝐴 ) ) )