1. (20pts) General classic propositional logic exercises. Use 7, -, A and V to express the following declarative sentences in propositional logic; in each case state what your respective propositional atoms p, q, etc. mean. (a) If the sun shines today, then it won't shine tomorrow. (b) If a request occurs, then either it will eventually be acknowledged, or the requesting process won't ever be able to make progress. (c) Today it will rain or shine, but not both. (d) If Dave met Sara yesterday, they had a cup of coffee together, or they took a walk in the park