RealInterval expression comparisons broken

[eviatarbach]

Expressions involving RealIntervals do not compare properly, returning a TypeError. For example,

sage: bool(RealInterval(4,5)*x==RealInterval(4,5)*x)
ERROR: An unexpected error occurred while tokenizing input
The following traceback may be corrupted or invalid
The error message is: ('EOF in multi-line statement', (1006, 0))
TypeError:

Component: symbolics

Issue created by migration from https://trac.sagemath.org/ticket/11613

[mwhansen]

comment:1

I think that this is invalid. Here is the relevant documentation:

Comparison operations (==,!=,<,<=,>,>=) return true if every value in
the first interval has the given relation to every value in the
second interval. The cmp(a, b) function works differently; it
compares two intervals lexicographically. (However, the behavior is
not specified if given a non-interval and an interval.)

So,

sage: RIF(3,4) == RIF(3,4)
False
sage: RIF(3,3) == RIF(3,3)
True

[eviatarbach]

comment:2

Oh, I see. The second bug is still valid though, so I will edit the ticket to reflect this.

[eviatarbach]

Description changed:

--- 
+++ 
@@ -1,13 +1,4 @@
-RealIntervalField (RIF) comparisons are broken. For example,
-
-```
-sage: RealInterval(4,5)==RealInterval(4,5)
-False
-sage: RIF(4,5)==RIF(4,5)
-False
-```
-
-A possibly related bug:
+Expressions involving RealIntervals do not compare properly, returning a TypeError. For example,
 
 ```
 sage: bool(RealInterval(4,5)*x==RealInterval(4,5)*x)