[VA] "Introducing APRIL !" microchallenge

[J-F Garnier]

Expressed in these terms, this challenge seems very vague, and almost impossible to investigate.
But - assuming it's a serious question, despite the white line - we can narrow the search with these considerations:
- the operation must be available on all cited machines,
- it is an arithmetic operation, excluding operations based on approximations (trig, log) and also excluding some operations that we know have problems on certain machines, such as >HMS.

Comparing the features of the two low-end machines, HP33E and 10C, we get:
- basic arithmetic operations: +, - , * and /
- 1/x, sqrt, x²
- pi, %
- INT, FRAC
- >DEG, >RAD
Furthermore (if we trust the author), the argument is in the range of 0.1..1500 excluding corner cases with very large or very small numbers.

Let's look closer at the suspects:
- the basic operations + - * and / are based on proven algorithms, and are at the bottom of our list of suspects,
- 1/x is just 1 divided by x, so belongs to the above category,
- same as x², that is x times x.
- sqrt could be a possible suspect, but again it relies on a solid algorithm,
- pi is just a constant, nothing special to expect here.
- % is basically divide by 100.
- INT and FRAC are simple operations, again nothing special to expect here.
- >DEG and >RAD are conversion operations, basically a multiplication or division, so we are back to the basic operation case.

It seems that all the suspects have good reasons to claim they are innocent.
We need to review again our list, but that will be for tomorrow...

J-F