Turbo Prolog

6 Tutorial IV: Arithmetic,
Simple Input and Output,
and Debugging
Turbo Prolog's arithmetic capabilities are similar to those provided in programming
languages such as BASIC, C and Pascal. It includes a full range of arithmetic functions and
standard predicates as diverse as the arctangent function, and a family of predicates for
bitwise logical operations. These are described in the first part of this chapter, along
with standard predicates for basic input and output of numeric and non-numeric values.
The final part of this chapter resumes the discussion of debugging at the point where
Chapter 2 left off. As programs become larger and more complex, you'll require more
control over the amount of information produced by the various trace facilities, and this
section tells how to gain that control.
PROLOG CAN DO ARITHMETIC TOO!
We have already seen some simple examples of Turbo Prolog's arithmetic capabilities.
Turbo Prolog can perform all four basic arithmetic operations (addition, subtraction,
multiplication and division) between integer and real values, the type of the result being
determined according to Table 6-1.
Table 6-1 Arithmetic Operations
Oeerand I Oeerator Oeerand 2 Result
integer +, -, * integer integer
real +, -, * integer real
integer +, -, * real real
real +, -, * real real
integer or real integer or real real
63