1 water is warm => I take shower 2 water is not cold (=water is warm)=> I take shower 3 water is warm => I take shower The question is more concerned with logical implications.

1 and 2 are almost identical in meaning, 3 is a little bit different though. 1 and 2 mean that you will definitely take a shower if the conditions are met (warm water or not cold water). But 3 states the conditions under which you *might* consider taking a shower. You will only be willing to take a shower if the water is warm. But you are not saying that you definitely *will* take a shower even if the water is warm. Even with warm water you might not take a shower. But you definitely will not take a shower if it's cold. 3 is a pretty subtle distinction from 1 and 2. By the way, you would say "the water" here, not just "water".

I'm not sure if you're still interested in a detailed answer, but I'll post it nonetheless: 1) If the water is warm, then I will take a shower. (Nothing is said about any other temperature though (cool, cold, freezing etc), so we do not specify if we are going to take a shower at any other condition (temperature), but we explicitly note that if it's exactly WARM, then we will DEFINITELY take a shower.) 2) If the water is anything BUT cold (i.e. it is warm, cool, freezing etc) I will DEFINITELY take a shower. The only condition that I don't take a shower is if the water is EXACTLY cold. (Note that "not cold" does NOT necessarily equal warm. As I've already specified above it can be warm, cool, freezing to name a few.) 3) If the water is warm I may or may not take a shower, BUT If you see me taking a shower, then you can be sure the water is warm, because I was only going to take it if the water was warm.

Thank you guys for your answers!