Problems with brackets in Exercise tool

Question

There is a problem with brackets in the exercise tool. If I try to solve problem 3 of the current exercise sheet, the right solutions are not accepted. I tried to solve the 3a with the teaching tool "Propositional Logic Tools" and transformed the expression "x ↔ (y1 ∧ y2)" into CNF. The showed solution of the tool is "x<->y1&y2: (x|!y1|!y2)&(!x|y2)&(!x|y1|!y2)". Here the brackets are missing so that this solution is wrong. If I enter this wrong solution in the exercise, it is accepted, which should not be the case.

Answer 1

I don't think that there are brackets missing. Note that the slides explain that we will always use the following precedences: ¬ < ∧ < ⊕ < ∨ < → < ↔ which means that negation binds strongest and equivalence binds weakest. Hence, you can write x ↔ (y1 ∧ y2) also as x ↔ y1 ∧ y2. The printer of the teaching tool avoids brackets as much as possible.