Homework 5: Parallelism and Control Flow

We also defined sequential and parallel versions of the structural operational dynamics, given by judgments e 7→seq e′ and e 7→par e′. These differ on the rules for evaluating pairs: while 7→seq evaluates the first component of a pair before the second, 7→par evaluates the two simultaneously. e1 7→seq e1 〈e1, e2〉 7→seq 〈e1, e2〉 (Pair-S1) e1 val e2 7→seq e2 〈e1, e2〉 7→seq 〈e1, e2〉 (Pair-S2) e1 7→par e1 e2 7→par e2 〈e1, e2〉 7→par 〈e1, e2〉 (Pair-P1) e1 val e2 7→par e2 〈e1, e2〉 7→par 〈e1, e2〉 (Pair-P2) e1 7→par e1 e2 val 〈e1, e2〉 7→par 〈e1, e2〉 (Pair-P3)