You are at a wedding reception in Knave City and are talking with someone (a knight, knave or liar) who makes the following statements:

Chris is married to Alice.

Either Alex is married to Coral or Bob is married to Alice but not both.

Either Alex isn't married to Betty or Chris isn't married to Coral but not both.

I am a knight.

The maid of honor (who is a knight) tells you whether the third statement is true or false. From that, you could figure out who is married to whom...