Logic

AX:(p(X) => q(X)) is an implication

What is False?

AX:EX:p(X,Y)

What is True

The property of a sentence that contains no variables

What is ground?

The property of a sentence that contains no free variables

What is closed?

The sentence AX:(p(X) => EY:q(X,Y)) has no free variables

What is true?

Size of Herbrand base for a language with 3 object constants and 1 binary relation constant

What is 9

Logical property of a sentence that is true in every truth assignment

What is validity

Logical property of (EX:p(X) => AX:p(X))

What is contingency

Logical property of AX:(p(X) => ~p(X))

What is contingency (p could be empty)

Logical property of (EX:p(X) => AX:q(X)) | (AX:q(X) => EX:r(X))

What is validity

AX:AY:p(X,Y) |= p(a,a)

What is true

AX:EY:p(X,Y) |= EY:AX:p(X,Y)

What is false

EY:AX:p(X,Y) |= AX:EY:p(X,Y)

What is true

AX:EY:p(X,Y) |= EY:AX:p(Y,X)

What is false

AX:(p(X) => EY:q(Y)) |= (EX:p(X) => EY:q(Y))

what is true

The name of the rule ~~phi |- phi

negation elimination

The name of the rule phi => psi, phi => ~psi |- ~phi

negation introduction

AX:p(a,X) |- p(a,a) is an acceptable application of Universal Elimination

what is true

AX:AY:p(X,Y) |- AX:p(X,b) is an acceptable application of Universal Elimination.

what is false

Delta |= phi if and only if Delta |- phi

what is true

First person on moon

Neil Armstrong

Naturalist who sailed on HMS Beagle.

Charles Darwin

The first national park in the United States

Yellowstone National Park

The person who discovered radium

Marie Curie

The only person to win a Nobel prize in two scientific fields

Marie Curie