On Apr 24, 4:06 pm, Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5- a470-7603bd3aa...@spamschutz.glglgl.de> wrote: > Am 24.04.2012 08:02 schrieb rusi: > > > On Apr 23, 9:34 am, Steven D'Aprano<steve > > +comp.lang.pyt...@pearwood.info> wrote: > > >> "is" is never ill-defined. "is" always, without exception, returns True > >> if the two operands are the same object, and False if they are not. This > >> is literally the simplest operator in Python. > > > Circular definition: In case you did not notice, 'is' and 'are' are > > (or is it is?) the same verb. > > Steven's definition tries not to define the "verb" "is", but it defines > the meanung of the *operator* 'is'. > > He says that 'a is b' iff a and be are *the same objects*. We don't need > to define the verb "to be", but the target of the definition is the > entity "object" and its identity.
Identity, sameness, equality and the verb to be are all about the same concept(s) and their definitions are *intrinsically* circular; see http://plato.stanford.edu/entries/identity/#2 And the seeming simplicity of the circular definitions hide the actual complexity of 'to be' for python: http://docs.python.org/reference/expressions.html#id26 (footnote 7) for math/philosophy: http://www.math.harvard.edu/~mazur/preprints/when_is_one.pdf -- http://mail.python.org/mailman/listinfo/python-list
