%--------------------------------------------------------------------------
% File     : CAT003-3 : TPTP v9.0.0. Released v1.0.0.
% Domain   : Category Theory
% Problem  : XY epimorphism => X epimorphism
% Version  : [Sco79] axioms : Reduced > Complete.
% English  : If xy is an epimorphism, then x is an epimorphism.

% Refs     : [Sco79] Scott (1979), Identity and Existence in Intuitionist L
% Source   : [ANL]
% Names    : p3.ver3.in [ANL]

% Status   : Unsatisfiable
% Rating   : 0.10 v8.1.0, 0.05 v7.5.0, 0.11 v7.4.0, 0.12 v7.3.0, 0.17 v7.1.0, 0.08 v7.0.0, 0.13 v6.3.0, 0.09 v6.2.0, 0.30 v6.1.0, 0.36 v6.0.0, 0.20 v5.5.0, 0.30 v5.3.0, 0.28 v5.2.0, 0.25 v5.1.0, 0.29 v5.0.0, 0.07 v4.1.0, 0.23 v4.0.1, 0.27 v4.0.0, 0.18 v3.7.0, 0.10 v3.5.0, 0.09 v3.4.0, 0.00 v3.3.0, 0.07 v3.2.0, 0.15 v3.1.0, 0.09 v2.7.0, 0.08 v2.6.0, 0.00 v2.5.0, 0.42 v2.4.0, 0.11 v2.2.1, 0.22 v2.2.0, 0.11 v2.1.0, 0.56 v2.0.0
% Syntax   : Number of clauses     :   22 (   7 unt;   2 nHn;  17 RR)
%            Number of literals    :   44 (  20 equ;  20 neg)
%            Maximal clause size   :    4 (   2 avg)
%            Maximal term depth    :    3 (   1 avg)
%            Number of predicates  :    3 (   2 usr;   0 prp; 1-2 aty)
%            Number of functors    :    8 (   8 usr;   4 con; 0-2 aty)
%            Number of variables   :   34 (   4 sgn)
% SPC      : CNF_UNS_RFO_SEQ_NHN

% Comments : Axioms simplified by Art Quaife.
%--------------------------------------------------------------------------
%----Include Scott's axioms for category theory
include('Axioms/CAT003-0.ax').
%--------------------------------------------------------------------------
cnf(assume_ab_exists,hypothesis,
    there_exists(compose(a,b)) ).

cnf(epimorphism,hypothesis,
    ( compose(X,compose(a,b)) != Y
    | compose(Z,compose(a,b)) != Y
    | X = Z ) ).

cnf(assume_h_exists,hypothesis,
    there_exists(h) ).

cnf(ha_equals_ga,hypothesis,
    compose(h,a) = compose(g,a) ).

cnf(prove_g_equals_h,negated_conjecture,
    g != h ).

%--------------------------------------------------------------------------