If not and Leaving out

If not adverb - Perhaps; indicating possibility of being more remarkable (greater or better or sooner) than.

Leaving out and if not are semantically related in other than topic. In some cases you can use "Leaving out" instead a preposition phrase "If not".

If not and leaving out are semantically related in other than topic. Sometimes you can use "If not" instead a preposition "Leaving out".