Add Reals set

[rikardn]

Implementation of the set of real numbers: Reals.

[isuruf]

Thanks for sending this PR. Got a couple of questions

[isuruf]

o could have complex values right?

[rikardn]

Thanks for pointing this out. I'll try to figure out how to do this. Ideas on how to handle complex numbers are welcome. I am thinking:

Interval, Empty - Must be real and can be handled as currently
FiniteSet - Can contain complex numbers. Could be handled directly
all others - Can contain complex numbers so create Intersection object

[isuruf]

Same here

[certik]

Thanks! There is a failure in https://travis-ci.org/github/symengine/symengine/jobs/727822895:

/home/travis/build/symengine/symengine/symengine/tests/printing/test_printing.cpp:692: FAILED:

  CHECK( latex(*l13) == "5 \\leq b \\wedge 2 \\leq a" )

with expansion:

  "2 \leq a \wedge 5 \leq b"

  ==

  "5 \leq b \wedge 2 \leq a"

/home/travis/build/symengine/symengine/symengine/tests/printing/test_printing.cpp:694: FAILED:

  CHECK( latex(*l14) == "b \\leq a \\wedge \\left(a \\neq c \\vee a = b\\right)" )

with expansion:

  "b \leq a \wedge \left(a = b \vee a \neq c\right)"

  ==

  "b \leq a \wedge \left(a \neq c \vee a = b\right)"

Not sure if it is related to this PR?

[rikardn]

The test failure seems to be related to this PR. I reverted and ran the tests without fail. I will try to resolve it.

[rikardn]

I see that I also missed adding Reals to is_a_Set. I'll do that.

[isuruf-bot]

Hi,

I've run clang-format and found that the code formatting is good.

Thanks for fixing the formatting.

[rikardn]

I have

• added Reals to is_a_Set
• Fixed the set_union and set_intersection to handle complex numbers
• Fixed the failing test. At least for now. It seems as if the failing was due to reversed ordering of a set.

[rikardn]

I see the code formatting issue. Is this fixed automatically or should I fix manually?

[certik]

You have to manually apply the commands from the message.

[isuruf]

Instead of checking if the value is a complex number here, we should check if the value is not a real number. For eg: symbols should be considered complex since we don't know what the value is going to be.

[rikardn]

Thanks for your patience! I have updated again:

• Fixed the FiniteSet union and intersection as suggested
• Added a proper contains method which was forgotten

The intersection doesn't fully work because of missing functionality in the set_intersection function. I don't know if you intend to have a separate class for intersections or if you want to solve it with unions and complements via deMorgan. In any case I don't know if anything else must be done about that in this PR.

[rikardn]

Now also the code coverage check passes. Are we good to go?

[isuruf]

Thanks for the PR