[FMFP] Remark on axiomatic semantics

semester4/fmfp/parts/06_exercises/02_fm/02_axiomatic-semantics.tex

@@ -8,6 +8,8 @@ This typically involves finding a loop invariant that holds before and after eac
 This invariant should mention every variable used in the loop.
 Any other variable should also be mentioned in it. The loop \textit{variant} may also be added for proving termination.
 A typical for-loop loop variant would be \texttt{n - x = Z}, as the next value of the loop variant has to be lower than the previous one.
+The preconditions and postconditions in the loops then reflect that the update to the loop variant variable(s) leads to them being smaller than $Z$,
+which allows proving that the loop variant is decreasing, signifying that the loop terminates \textit{eventually}.
 Of course, if \texttt{x} is decreasing, it itself can become the variant, as it fulfils the condition.
 
 Proof outlines work by providing post and pre-condition for each sub-statement in a statement.