Metamath Proof Explorer


Theorem frnsuppeq

Description: Two ways of writing the support of a function with known codomain. (Contributed by Stefan O'Rear, 9-Jul-2015) (Revised by AV, 7-Jul-2019)

Ref Expression
Assertion frnsuppeq I V Z W F : I S F supp Z = F -1 S Z

Proof

Step Hyp Ref Expression
1 fex F : I S I V F V
2 1 expcom I V F : I S F V
3 2 adantr I V Z W F : I S F V
4 3 imp I V Z W F : I S F V
5 simplr I V Z W F : I S Z W
6 suppimacnv F V Z W F supp Z = F -1 V Z
7 4 5 6 syl2anc I V Z W F : I S F supp Z = F -1 V Z
8 ffun F : I S Fun F
9 inpreima Fun F F -1 S V Z = F -1 S F -1 V Z
10 8 9 syl F : I S F -1 S V Z = F -1 S F -1 V Z
11 cnvimass F -1 V Z dom F
12 fdm F : I S dom F = I
13 fimacnv F : I S F -1 S = I
14 12 13 eqtr4d F : I S dom F = F -1 S
15 11 14 sseqtrid F : I S F -1 V Z F -1 S
16 sseqin2 F -1 V Z F -1 S F -1 S F -1 V Z = F -1 V Z
17 15 16 sylib F : I S F -1 S F -1 V Z = F -1 V Z
18 10 17 eqtrd F : I S F -1 S V Z = F -1 V Z
19 invdif S V Z = S Z
20 19 imaeq2i F -1 S V Z = F -1 S Z
21 18 20 eqtr3di F : I S F -1 V Z = F -1 S Z
22 21 adantl I V Z W F : I S F -1 V Z = F -1 S Z
23 7 22 eqtrd I V Z W F : I S F supp Z = F -1 S Z
24 23 ex I V Z W F : I S F supp Z = F -1 S Z