What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: If Barbara writes a letter, then it is cold. If it is cold, then it is cloudy. If it is cloudy, then James is playing a game. Barbara is writing a letter.
It is cold can be inferred via the modus ponens rule. If Barbara writes a letter, then it is cloudy can be inferred via the transitivity rule. If it is cold, then James is playing a game can be inferred via the transitivity rule.