And the lesson is – express yourself carefully – do not use Os for 0s and put parentheses in (2x)/(3y). Mathematicians know that. In Hardy/Littlewood book of math jokes, the professor (Hardy?) writes down an equation:
a x^4 + b x^3 + c x^2 + d x + e (similarly to ax + b, ax^2+bx+c, etc)
and then finds it necessary to add:
when e is any number, not necessarily the ln(1)
and then adds further
although it could take that value.
That’s _precision_ of speech.