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Description: Preimage of a difference. (Contributed by Mario Carneiro, 14-Jun-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | difpreima | ⊢ ( Fun 𝐹 → ( ◡ 𝐹 “ ( 𝐴 ∖ 𝐵 ) ) = ( ( ◡ 𝐹 “ 𝐴 ) ∖ ( ◡ 𝐹 “ 𝐵 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funcnvcnv | ⊢ ( Fun 𝐹 → Fun ◡ ◡ 𝐹 ) | |
| 2 | imadif | ⊢ ( Fun ◡ ◡ 𝐹 → ( ◡ 𝐹 “ ( 𝐴 ∖ 𝐵 ) ) = ( ( ◡ 𝐹 “ 𝐴 ) ∖ ( ◡ 𝐹 “ 𝐵 ) ) ) | |
| 3 | 1 2 | syl | ⊢ ( Fun 𝐹 → ( ◡ 𝐹 “ ( 𝐴 ∖ 𝐵 ) ) = ( ( ◡ 𝐹 “ 𝐴 ) ∖ ( ◡ 𝐹 “ 𝐵 ) ) ) |