Let alone and Without

Let alone conjunction - To say nothing of.

Without and let alone are semantically related in part of speech topic. In some cases you can replace term "Without" with "Let alone", this conjunctions are similar, when it comes to topics like except.

Without preposition - Not having.

Let alone and without are semantically related in part of speech topic. Sometimes you can replace term "Let alone" with "Without", this prepositions are similar, if it concerns topics such as except.