Top level predicate and output format:
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The top level predicate name should be <typecheck(X)> which will take
the program as a string as input (unifies the string with the variable
X) and print out whether the given program is well-typed (meaning
there is no type error). For example,

?- phrase(typecheck(Z),`int a, b, c; c= b*3; a = b+c;`).

will produce the following output:

		Z = [The program is well-typed.]
		
If the program is not well-typed (there is some type error), then the
output should start with the string "Type mismatch: " followed by the
statement where type was mismatched. For example,

?-        phrase(typecheck(Z),`int a, b; float c; a= b*3; a = b+c;`).

will produce the following output:

		Z = [Type mismatch: a = b+c;]
		
Note that if the program contains multiple type mismatch error,
identifying the first line where the mismatch occurs and print it out
is a mandatory part of the assignment.  You do not have to identify
the remaining errors (after the first mismatch) in the program.

Since we are planning to use Web-CAT for automatic grading of the
assignment, please ensure to use the printing format mentioned above.