Provide a derivation for b A right arrow B C B A right arro
Provide a derivation for b) (A right arrow B) & C; (B A) right arrow D; (B right arrow A)/D
Solution
a) ~P->~Q is given
we will use the result that ~A->~B and B->A are equivalent
so, as ~P->~Q we can say that Q->P
using modus ponens, Q and Q->P we can say that P is true
as P is true PVR will definitely be true.
b) A->B &C is given
So, A->B is true (1)
C is true (2)
further, B->A is given (3)
from (1) and (3) we can say that A<->B (4) and also B<->A (5)
Given (B<->A) ->D (6)
from (5) and (6) using modus ponens rule we can conclude that D is true
