[10 marks] this question asks you to examine the formal definitions of a tm and related concepts closely. based on these definitions, answer the following. (a) a configuration of a turing machine (tm) consists of three things. what are these three things? (b) can input alphabet σ contain the blank symbol t? why or why not? (c) the tape is infinite. is the tape alphabet infinite? (d) can a turing machine’s head ever be in the same location in two successive steps? (e) what is the difference between a decidable language and a turing-recognizable language?