1. The problem statement, all variables and given/known data extension theorem "A "subsentence" of a given sentence is a sentence that‘s a part of the given sentence, where we count a sentence as a part of itself. A "proper subsentence" of a given sentence is a subsentence of the given sentence other than itself." i don't understand "subsentence of the given sentence other than itself" could anyone give me some example to make me understand? i'm studying mathematical logic, but i think this question is more to language than math. I don't know if it is legal to post question like this, since i don't know any active linguistic forum,and lazy to find one, ;P, i hope someone help me with this. and if it is illegal, tell me.