Let-be Definition

verb

To not disturb or meddle with; to leave (someone or something) alone.

Will you never let me be?
Wiktionary

(intransitive, archaic) To stop, to stop doing something; to leave off (now used alone, formerly also + infinitive).

Wiktionary

(mathematics) Used to assign a value to a symbol.

Let f be any real-valued function on I and g be any real-valued function on J.
Wiktionary