Where is the != >= > <= operators defined in STL?

[PengYu.UT]

I heard that != >= > <= operators are defined based on the operator ==
<.

Could you tell me which header file defines the four operators?

Best wishes,
Peng

 

[Victor Bazarov]

I heard that != >= > <= operators are defined based on the operator ==
<.

Could you tell me which header file defines the four operators?

<utility>