Exercise · ZW-PREDICATE-009 · ★★★ Advanced
Which of these expressions is an open predicate?
Choose one option.
Show answer
- B. x+1=2
Explanation
\(x+1=2\) has the free variable \(x\), so its truth depends on it. \(2+2=4\) and «Madrid is a city» are closed propositions, and the question has no truth value.
Review the concept: Predicate
A predicate \(P(x)\) is an expression with free variables that becomes a proposition when values are assigned to them.
\[P(x,y)\in\{\top,\bot\}\]
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