Question Number 2 [4+4]:

1. If S is Y=X+1; Z=Y-3 and Q is Z=10 then compute the weakest precondition W_p(S,Q). Also, find the weakest precondition W_p(S,Q) for the following two conditional statements:

	If (X<6) X=X*X; else X=X+1; {X>=9}		If (X!=0) Z=X; else Z=X+1; {Z>0}

4. Use algebraic specification techniques to define Constructors, Inspectors and Axioms for Hash table data structure. Write all possible and impossible Axioms on given data structure.