Motion 31 (proposed Level 1 text V04.2) and Boolean functions
In §5.6.9 and Table 5, ⊂ (U+2282 SUBSET OF) is used for
containedInInterior, while this symbol usually means either
"subset of" or "proper subset of" (i.e. subset of but not equal).
See <http://en.wikipedia.org/wiki/ISO_31-11>.
There could also be: isBounded and isSingleton.
Comparisons mainly come from Motion 13.04, but a weakness of this
motion was that it gave an implementation, not the meaning as set
(or topological space) functions.
I wonder whether precedesEqual(A,B) and precedes(A,B) should be true
if A and/or B is empty, because they should respectively be equivalent
to: for all a in A and all b in B, a <= b (resp. a < b). But they
would no longer be transitive.
I agree that lessEqual(Empty,Empty) should be true, though Motion 13.04
said that the result is false. Then lessEqual(A,B) is equivalent to:
for all a in A, there exists b in B such that a <= b
and
for all b in B, there exists a in A such that a <= b
--
Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <http://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)