A double negative employs two negatives in the same sentence so that they cancel each other and create a positive. In Shakespeare's day, double negatives were considered emphatic, but today, they are considered grammar mistakes.
Solve a grammar issue forever by creating a grammar rule! You will also receive 50 000 pro credits worth $5! Read here how!
Double Negative - indefinite pronoun + frequency adverb
Will need to verify if suggestion is a word against a dictionary (eg "not unidirectional" would be a nonsense suggestion.)