Is the following DFD valid? If not, please tell us what is wrong.

Why not make all variables global instead of just global within particular contexts, since global variables may be used everywhere in the program?Justify your answer.

The block of compound statements (if or for statements) can be specified using curly braces or keywords approach such as end if or end for statements in different  programming languages. Write in your own words, which approach can help in  improving readability with giving some examples???

To what extent is it appropriate to combine select statements from the same table?

** **** Exercise: 3 stars, standard (swap_exercise)     Write an Imp program [c] that swaps the values of [X] and [Y] and    show that it satisfies the following specification:       {{X <= Y}} c {{Y <= X}}     Your proof should not need to use [unfold valid_hoare_triple].     Hints:       - Remember that Imp commands need to be enclosed in <{...}>         brackets.       - Remember that the assignment rule works best when it's         applied "back to front," from the postcondition to the         precondition.  So your proof will want to start at the end         and work back to the beginning of your program.       - Remember that [eapply] is your friend.)  *) Definition swap_program : com  (* REPLACE THIS LINE WITH ":= _your_definition_ ." *). Admitted. Theorem swap_exercise :  {{X <= Y}}    swap_program  {{Y <= X}}.Proof.  (* FILL IN HERE *) Admitted.(** [] *)From the book software Foundations Volume 2 coq proof

Program using C++ language without the use of logical operators(&&,||,!). Also, be careful with the operations! Because this RetailCost=(units*99)*.50; gives a warning and does not print out total cost purchase.

Give an example of a while loop, then provide the equivalent do-while loop and for loop.  Then give a different example of a do-while loop, along with the equivalent while loop and for loop. Finally, give an example of a for loop, along with the equivalent while loop and do-while loop. Use your examples to illustrate the advantages and disadvantages of each looping structure, and describe those advantages and disadvantages.

3, A lecturer intends to separate his students into 2 groups based on their INDEX Numbers, those with odd numbers in group A and EVEN numbers in B. Use if-else statement to implement this

Some one please explain what is "where z′ is the value of z after the statement is executed" given in the question. CAN SOME ONE PLEASE SOLVE THIS QUESTION CORRECTLY WITH PROPER EXPLANATION OF WHICH CONDITION TO CONSIDER.