Changes between Version 1 and Version 2 of Ticket #14471, comment 13


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Timestamp:
04/24/13 02:37:45 (9 years ago)
Author:
nbruin
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  • Ticket #14471, comment 13

    v1 v2  
    3636
    3737Furthermore, note that `type(parent(m))` inherits from `UniqueRepresentation` but that `type(parent(f))` does not.  It doesn't seem easy to do, but it might be possible to make two equal-but-not-identical callable expression rings. Building matrix rings over them will wreak havoc, because the constructor will use equality testing on the ingredients (and hence return identical matrix rings), but the coercion framework will not honour "equality" between the non-identical base rings.
     38
     39'''EDIT:''' The last bit is not the case. `CallableSymbolicExpressionRing` is a `UniqueFactory`. Furthermore, it seems the coercion framework does detect "equal but nonidentical" parent and can sometimes figure out coercions between them.