This is an assignment from Introduction to Artificial Intelligence class

Construct a knowledge base KB consisting of the following sentences in propositional logic: If the unicorn is mythical, then it is immortal, but if it is not mythical, then it is a mortal mammal. If the unicorn is either immortal or a mammal, then it is horned. The unicorn is magical if it is horned. Prove or disprove the following, each using two methods: By constructing a truth table, and by using the logical equivalence and inference rules. The unicorn is mythical. The unicorn is magical. The unicorn is horned