1. Assume a, b, c ∈ Z. Prove the following deduction: 6a ∼= 5b (mod 4c), (2c) |(3a), ∴ c |(5b). b. Assume A and B are se
Posted: Thu May 12, 2022 9:46 am
1. Assume a, b, c ∈ Z. Prove the following deduction:
6a ∼= 5b (mod 4c), (2c) |(3a), ∴ c |(5b).
b. Assume A and B are sets. Suppose f : A → B is a
function, that X ⊂ B and that Y ⊂ B.
Prove that f -1 (X ∪ Y ) ⊂ f
-1 (X) ∪ f -1 (Y ).
6a ∼= 5b (mod 4c), (2c) |(3a), ∴ c |(5b).
b. Assume A and B are sets. Suppose f : A → B is a
function, that X ⊂ B and that Y ⊂ B.
Prove that f -1 (X ∪ Y ) ⊂ f
-1 (X) ∪ f -1 (Y ).