File 0-object_like_macro.h is a header file that defines a macro named SIZE as an abbreviation for the token 1024.
File 1-pi.h is a header file that defines a macro named PI as an abbreviation for the token 3.14159265359.
File 2-main.c is a program that prints the name of the file it was compiled from, followed by a new line.
File 3-function_like_macro.h is a function-like macro ABS(x) that computes the absolute value of a number x.
File 4-sum.h is a function-like macro SUM(x, y) that computes the sum of the numbers x and y.