SYMBOLIC LOGIC



SYMBOLIC LOGIC

RULES OF INFERENCE VS. RULES OF DEDUCTION

RULES OF DEDUCTION

RULES OF INFERENCE RULES OF REPLACEMENT

allow you to infer one formula allow you to replace one

(expression of a fact) from formula with an equivalent

another. formula, or vice-versa

are not reversible. are reversible

p & q ~~p

p p

but not and

p p

p & q ~~p

can only be used in a formula if they can be used to replace

correspond to the main connective of any part of a formula, no

that formula matt

If you have

p & q p ( (q & ~~r)

you can use “Simplification” p ( (q & r)

to derive p

cannot be used in one part of a line can be used to replace either

or formula, (1) a formula that takes up an

entire line of a deduction or

(2) a part of a formula.

If you have If you have

(p & q) ( r (~~p & q) ( r

you cannot derive you can derive

p ( r (p & q) ( r

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download