Solution to 5.

 

The yellow substance is an acid, if and only if, if it reacts with a base then a salt is produced. If a salt is produced, then either the yellow substance is an acid, or both the yellow substance is a base and the experiment is flawed. The experiment is not flawed and the yellow substance is not a base. Furthermore, and salt is produced. Therefore, the yellow substance is an acid.

Y = The yellow substance is an acid.

R = The yellow substance reacts with a base.

S = A salt is produced.

B = The yellow substance is a base.

F = The exxperiment is flawed.

Substituting, we get:

 

Y if and only if, if R then S

If S, then either Y or both B and F

Not-F and not-B

S

Therefore, Y

 

These are all easy to symbolize:

 

y<->(r->s)

s->{yv(b&f)}

~f&~b

s

.:y