For the following seqent contruct a derivation of its conclu

For the following seqent contruct a derivation of its conclusion from its premises.

[P ?( Q ? R)] ? (S ? T) ? P ? [Q ? (R ? S)]

EXAMPLE

Solution

1. [P ( Q R)] (S T)

2. (S T)

3. [P ( Q R)]

by 2. using Simplification

4. S

5. T

by 3 Using Simplification

6. P

7. ( Q R)

Using 7. Simplification

8. Q

9. R

Using 4,6,8,9

P [Q (R S)]