Translating from English to First-Order Logic:
Still we have now seen some of examples of first order sentences, than you should practice writing down English sentences in first-order logic, just to get used to them.
There are many types of ways to translate things from English to Predicate Logic incorrectly, that we can highlight some pitfalls to avoid. So firstly, there is a lot a mix up between the "and" and "or" connectives. That we saw in a previous lecture that the sentence "Every Monday and Wednesday I go to John's house for dinner" can be written in first order first-order logic just as: So there it's important to note that the "and" in the English sentence now has changed to an "or" sign in the first-order logic translation. This means that we have turned this sentence into an implication, if the day of the week is Monday or Wednesday we need to make it clear this, after then we go to John's house for dinner. So now the disjunction sign (the "or" sign) is introduced. Notify that we call the "and" sign the conjunction sign.
And the another common problem is getting the choice, is just placement and order of the quantifiers wrong. Rather than this we saw that with the Red Lion meals example above. As according to another example, trying translating the sentence: "Only red things are in the bag". So here are some incorrect answers: