I’m very sure "_⊆_” is not symmetric, everything else is still open questions.
> On 27 Feb 2015, at 01:12, Robbert van Dalen <[email protected]> wrote: > > Hi, > > I have the following code the returns true on “test" > > "field1" is a new field atom; > "field2" is a new field atom; > > class "A" extends object > with fields > field1 : number; > field2 : float; > > class "B" extends object > with fields > field1 : float; > field2 : number; > > Public method "test" is > [ > B ⊆ A > ]; > > Shouldn't both B ⊆ A and A ⊆ B return false? > Is the subtype/supertype relation symmetric? > > Or alternatively, should "_⊆_" return a three-valued result? i.e. > false/true/don’t know. > > cheers, > Robbert.
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