update explanation of approx_check

Author: LorrensP-2158466

tests/pass/float.rs

@@ -12,15 +12,16 @@ use std::fmt::{Debug, Display, LowerHex};
 use std::hint::black_box;
 use std::{f32, f64};
 
-/// Another form of checking if 2 floating point numbers are almost equal to eachother
+/// Another way of checking if 2 floating point numbers are almost equal to eachother.
 /// Using `a` and `b` as floating point numbers:
 ///
 /// Instead of doing a simple EPSILON check (which we did at first):
 /// Absolute difference of `a` and `b` can't be greater than some E (10^-6, ...).
+/// `(a - b).asb() <= E`
 ///
-/// We look at ULP: `Units in the Last Place` or `Units of Least Precision`
+/// We will now use ULP: `Units in the Last Place` or `Units of Least Precision`
 /// It is the absolute difference of the *unsigned integer* representation of `a` and `b`.
-/// For example for f32, which in IEEE format looks like this:
+/// For example checking 2 f32's, which in IEEE format looks like this:
 ///
 /// s: sign bit
 /// e: exponent bits
@@ -33,11 +34,11 @@ use std::{f32, f64};
 /// Same with exponents but no zero checking.
 ///
 /// So when Sign and Exponent are the same, we can get a reasonable ULP value
-/// by doing the operation explained above. And if this is less than or equal to our chosen upper bound
+/// by doing the absolute difference, and if this is less than or equal to our chosen upper bound
 /// we can say that `a` and `b` are approximately equal.
 ///
 /// Basically ULP can be seen as a distance metric of floating point numbers, but having
-/// the same amount of "spacing" between consecutive numbers. So eventhough 2 very large floating point numbers
+/// the same amount of "spacing" between all consecutive representable values. So eventhough 2 very large floating point numbers
 /// have a large value difference, their ULP can still be 1, so they are still "approximatly equal",
 /// but the EPSILON check would have failed.
 macro_rules! assert_approx_eq {