breaking change?: what do do with range equality? What is 'undefined'? about tck HOT 4 OPEN

Not sure where the confusion is coming from. The operational semantics of unary tests and ranges are well defined in Table 55: Semantics of decision table syntax. The ones for the relational operators in Tables 52, 53, and 54.

Based on the above <=5 and (null, 5] evaluate to different results hence they are not equivalent, hence cannot be equal, it would break the substitution principle.

The undefined should probably be replaced with + /- infinity so that these constructions make any sense from the mathematical point of view.

from tck.

From discussion on the meeting, this is correct: "I have a feeling that perhaps (<= 10) = (null..10] is now supposed to be false ... but <=10.start might still return null"

from tck.