I am taking a logic class and we are getting into Predicate Logic and i have no idea how to do it can someone help me?
You can use Universal Instantiation, Conditional Proof, Conjunction Introduction (P, Q l- (P & Q)), and Universal Generalization.lazycritic said:V(universal quantifier)xFx |- VxGx--->Vx(Fx & Gx)
Is "-" negation or part of the quantifiers? "~" is negation, A and E are quantifiers.3. -](makeshift particular quantifier)x]yLxy |- Vx-Lxx
Quantifier exchange...but how do I get rid of the y?
4. |- -]xFx v Vx-Fx
Sorry, I'm not sure how to get rid of the y either.lazycritic said:According to your definitions, those problems look like:
3. ~Ex EyLxy |-Ax ~Lxx (close to the same thing)
Double negation. What is ~~Ax(~Fx)? Or ~~Ex(Fx)?4.|- ExFx v Ax ~Fx (looks like my post had a typo - no negation on the first existential quantifier)
Looks good.2. Fa AE
3. | Ga
4. | Ga & Fa
5. Ga ---> Ga & Fa
6. Ga ---> Fa & Ga
7. AxGx--->Ax(Fx & Gx)
3. ~Ex EyLxy |-Ax ~LxxHurkyl said:For #3, can't you use this?
Or some sort of substitution rule?