# Changes between Initial Version and Version 16 of Ticket #11506

Ignore:
Timestamp:
May 20, 2014, 6:07:26 PM (9 years ago)
Comment:

Also, the following two are equally incorrect:

```sage: infinity == unsigned_infinity
True
sage: 2+7 == Mod(2,7)
True
```

Both violate Python rules for equality and hashes. But as long as we want the latter we also have to accept the former.

Unmodified
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Modified
• ## Ticket #11506

• Property Reviewers changed from to `Peter Bruin`
• Property Authors changed from to `Volker Braun`
• Property Priority changed from `major` to `critical`
• Property Dependencies changed from to `13125`
• Property Branch changed from to `u/vbraun/infinity_ring`
• Property Milestone changed from `sage-5.11` to `sage-6.3`
• Property Commit changed from to `cd9242959af9fda6d5351f8410889b36d6b6a392`
• ## Ticket #11506 – Description

 initial Comparisons in the infinity ring are broken, mostly because it does not correctly coerce infinities from other rings into it. It also needs to be updated for the new coercion framework. A sampler of oddities: {{{ sage: infinity == unsigned_infinity True sage: oo == CC(oo) False sage: CC(oo) == RR(oo)  # ok because it doesn't involve InfinityRing True sage: InfinityRing( CC(oo) ) A positive finite number sage: InfinityRing( SR(oo) ) A positive finite number }}} Also, `sage/rings/infinity.py` has no author or copyright notice. Also, `sage/rings/infinity.py` has no author or copyright notice. Comparisons with SR or complex fields are still sometimes weird as * SR doesn't coerce to the infinity ring, since we want symbolic comparisons with infinity * Complex numbers have phases, but the infinity ring only supports +/- * CC/CDF have a weird model for their own infinity representation: These shall be dealt with elsewhere as they can't be fixed on the side of the infinity ring.