效绵鼎 RE's:Definition-(2) Induction 1:If E and E2 are regular expressions, then E+E2 is a regular expression,and L(E+E2)= L(EOLE2). Induction 2:If E and E2 are regular expressions, then E E2 is a regular expression,and L(E E2)= L(E1)L(E2). Induction 3:If E is a RE,then E*is a RE,and L(E*)=(L(E)* 77 RE’s: Definition – (2) ◼ Induction 1: If E1 and E2 are regular expressions, then E1+E2 is a regular expression, and L(E1+E2 ) = L(E1 )L(E2 ). ◼ Induction 2: If E1 and E2 are regular expressions, then E1E2 is a regular expression, and L(E1E2 ) = L(E1 )L(E2 ). ◼ Induction 3: If E is a RE, then E* is a RE, and L(E*) = (L(E))*