**E** is a theorem prover for full first-order logic with
equality. It accepts a problem specification, typically
consisting of a number of first-order clauses or formulas,
and a conjecture, again either in clausal or full
first-order form. The system will then try to find a formal
proof for the conjecture, assuming the axioms.

If a proof is found, the system can provide a detailed list of proof steps that can be individually verified. If the conjecture is existential (i.e. it is of the form "there exists an X with property P"), more recent versions can also provide possible answers (values for X).

Development of E started as part of the E-SETHEO project at TUM. The first public release was in in 1998, and the system has been continuously improved ever since. I believe that E now is one of the most powerful and friendly reasoning systems for first-order logic. The prover has successfully participated in many competitions.

2.6

release

**E** 2.6 *Floral Guranse* is now
available. The main changes relative to E 2.5 are full support
for TFX, nearly full support for TH0 syntax (and some support
for higher-order reasoning), more search heuristics, some
faster algorithms, and improved automatic modes.

The new version is available from the Download page.

**E** 2.5 *Avongrove* (pre-release) has
won the UEQ and LTB divisions
of CASC-J10. It
has also won third places in FOF and (rather by accident)
FNT. E also was the reasoning engine of Enigma, which came
in second in FOF. The official release will be available
immediately. It also is available via
the public
github repository.