Le 11-févr.-09 à 23:53, Professor James Davenport a écrit :
You are absolutely right Robert, and I fear that both OpenMath and MathML content are having subset_suchthat (the set of things inside a reference set such that some condition holds) but miss set_of_expressions_such_thatThe reason fro this, as I recall, is to avoid Russell's paradox.
But you do not hit the Russel's paradox since the set_of_expressions_such_that( x, domain, f ) = map(f,suchthat(x,domain))The issue is having to use map, I think where one wishes to speak of the set of function-results and not speak about applying f to the set.
Map sounds like it should be called range to me... but that is superficial.
paul
To serve the purpose below ( {[0,x] | x in R} )Surely this is map(lambda x.interval(0,x),R).and many others where basically one constructs a set by applying functions to a few other sets. I think { [x,y] | x in R and y in R } is even more difficult.Non-trivial, but basically because cartesian product don't have deconstructors. map(lambda z,interval(z.first,z.second),cartesian_product(R,R)) is basicaly what is wanted.
smime.p7s
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