Fallacious disjunctive syllogism

Affirmation of an inclusive disjunction

Fallacious disjunctive syllogism is a formal fallacy that consists of concluding that given the possibility of one thing or the other (or both), then if one occurs, the other does not exist.

Examples:

I told him he could eat or drink if he wanted to… he’s eating, so he’s not drinking. -

shape:

C is known to occur if A is true or B is true (or both) C happens and since A is true, B must be false

Note: The disjunctive syllogism is valid when it comes to an exclusive disjunction, ex: or it snows or rain