newRPL - build 1255 released! [updated to 1299]

[Claudio L.]

(07-31-2019 07:08 PM)The Shadow Wrote:  Not really an issue, unless I'm missing something:

'LN(X) | X>1' is the same as 'LN(X) | X-1>0'. For that matter, it's the same as:

'LN(X+1) | X>0'

That's exactly what I had in mind, you simplified in 2 lines what took me a couple paragraphs to describe... you could probably code newRPL in half the size!
The thing is, if the system does an internal (transparent) variable substitution as you and I described, the current framework (which has only hints that can be >0 =0 or <0) works without modification, hence little additional effort for me to code it.
Following your example, the user provides 'LN(X) | X>1', the system internally converts it to 'LN(X+1) | X:R>0' and now the rules engine can use those hints to infer for example that the result of X+1 if X is R>0 is another R>0, therefore its LN(R>0) is Real otherwise the result would have to be assumed complex. The rules engine is not smart enough to know if (X+1)>1 (which could help refine the scope of LN() by saying if the result is R>=0 or R<0, because that requires to actually compute the expression X+1 or simplify the expression (X+1)-1, neither of them can be done from within the rules engine.