I consider that Business Rules are the business's rules, that is, policies determined by the business, i.e. specifically by business experts and those in charge of the business, who are likely non-programmers. (https://en.wikipedia.org/wiki/Business_rule)
I consider that logic is programming and thus associated more with IT than business leaders and domain experts, and therefore, Business Logic is the embodiment of (some of) Business Rules in IT systems and applications. (https://en.wikipedia.org/wiki/Business_logic)
Being rather different things, it would be a mistake to merge the terms Business Rules and Business Logic.
(A rules engine, combined with a set of rules for it (in whatever specific and limited form the engine takes) is an embodiment of business logic (but there will have to be other business logic as rules engines broadly can't accommodate all of a business's rules). It is often the case that IT takes over common terms and gives them more limited meaning, such as thinking of Business Rules as the actual rules (i.e. programming) that you'd feed to a rules engine! Rules engines execute rules-engine rules (programming), not Business Rules.)