The first number for the calculation.
The second number for the calculation.
The direction of the calculation. If "max", the values of a and b are switched.
The tolerance level to check if a and b are approximately equal.
a and b.
If a and b are approximately equal (within tol), it returns 0.
If the minimum absolute value of a and b is less than tol, or if either a or b is Infinity,
or if a and b have different signs, or if either a or b is NaN, it returns Infinity.
Otherwise, it returns the relative difference between a and b divided by the minimum absolute
value of a and b, rounded to 7 decimal places.
If the result is -0, it converts it to 0.
This function calculates the gap between two numbers,
aandb, based on the given directiondirand tolerancetol.