Recent questions tagged first-order-logic

3 votes
1 answer
92
Which of the following is a valid inference of $\mathrm{X, Y}$ in first-order logic?$$\begin{aligned}& \text{X}: \forall x .(\mathrm{P}(x) \rightarrow \mathrm{Q}(x)) \\& ...
3 votes
3 answers
104
3 votes
1 answer
107
Assume the following predicate and constant symbols.$W(x,y) :\; x$ wrote $y$$L(x,y) :\; x$ is longer than $y$$h :$ Hardy$a :$ Austen$j :$ Jude the Obscure$p :$ Pride and ...
2 votes
1 answer
108
Let the universe for all quantified variables be the set of all novels. Assume the following predicates and constant symbols:$W(x,y) :\; x$ wrote novel $y$$L(x,y) : \;x$ ...
3 votes
1 answer
109
Working with a unary predicate symbol, $P,$ a binary predicate symbol $Q$ and a unary function symbol $f,$ consider the following interpretation $M,$ given by,Universe $A...
3 votes
1 answer
110
Recall that a "sentence/proposition" is a predicate logic formula that has no free variables.In predicate logic, a set of sentences is satisfiable iff there is some inter...