Proposition(命题) A proposition/statement is a sentence that is true or false (might be unknown),but not both My salary of this month is greater than that of last month. Today is Tuesday,and it is raining. Can you speak English? 3-x=5 Every even integer greater than 2 can be expressed as the sum of two primes "What I'm talking now is fake." paradoxis a sentence that is true or false (might be unknown), but not both Proposition（命题） A proposition/statement My salary of this month is greater than that of last month. Today is Tuesday, and it is raining. Can you speak English? 3-x=5 Every even integer greater than 2 can be expressed as the sum of two primes “What I’m talking now is fake.” paradox