Where D is decideable and SD is semi-decideable

True or False. Briefly explain. (a). If L is in D and L2 is in SD then LiL must be in D. (b). If L is in D and L2 is in SD then LiL must be in SD. (c). If Li and L are in D, then L1 – L must be in D. (d). If L and L, are not in D, then L1 – L2 cannot be regular. (e). If Li and L, are not in D, then Liu L2 cannot be in D. Show transcribed image text True or False. Briefly explain. (a). If L is in D and L2 is in SD then LiL must be in D. (b). If L is in D and L2 is in SD then LiL must be in SD. (c). If Li and L are in D, then L1 – L must be in D. (d). If L and L, are not in D, then L1 – L2 cannot be regular. (e). If Li and L, are not in D, then Liu L2 cannot be in D.

## Expert Answer

Answer to True or False. Briefly explain. (a). If L is in D and L2 is in SD then LiL must be in D. (b). If L is in D and L2 is in …