Write the duals of the following statements :
(i) `( p vv q) ^^t` (ii) ` p vv t) ^^ r` (iii) ` ( p vv q) vv c`
Where t denotes tautology and c denotes contradiction.

Explanation

To find the duals of the given statements, we will follow the rules of duality in propositional logic. The rules are as follows:

1. Replace every conjunction (AND, denoted by `^^`) with disjunction (OR, denoted by `vv`).
2. Replace every disjunction (OR, denoted by `vv`) with conjunction (AND, denoted by `^^`).
3. Replace tautology (denoted by `t`) with contradiction (denoted by `c`).
4. Replace contradiction (denoted by `c`) with tautology (denoted by `t`).

Now, let's apply these rules to each of the statements.
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