%   ORIGINAL: h4/string/STRCAT__EQ__EMPTY
% Assm: HL_TRUTH: T
% Assm: HL_FALSITY: ~F
% Assm: HL_BOOL_CASES: !t. (t <=> T) \/ (t <=> F)
% Assm: HL_EXT: !f g. (!x. f x = g x) ==> f = g
% Assm: h4/list/APPEND__eq__NIL_c1: !l2 l1. h4/list/APPEND l1 l2 = h4/list/NIL <=> l1 = h4/list/NIL /\ l2 = h4/list/NIL
% Goal: !l2 l1. h4/list/APPEND l1 l2 = h4/list/NIL <=> l1 = h4/list/NIL /\ l2 = h4/list/NIL
%   PROCESSED
% Assm [HLu_TRUTH]: T
% Assm [HLu_FALSITY]: ~F
% Assm [HLu_BOOLu_CASES]: !t. (t <=> T) \/ (t <=> F)
% Assm [HLu_EXT]: !f g. (!x. happ f x = happ g x) ==> f = g
% Assm [h4s_lists_APPENDu_u_equ_u_NILu_c1]: !l2 l1. h4/list/APPEND l1 l2 = h4/list/NIL <=> l1 = h4/list/NIL /\ l2 = h4/list/NIL
% Goal: !l2 l1. h4/list/APPEND l1 l2 = h4/list/NIL <=> l1 = h4/list/NIL /\ l2 = h4/list/NIL
fof(aHLu_TRUTH, axiom, p(s(t_bool,t))).
fof(aHLu_FALSITY, axiom, ~ (p(s(t_bool,f)))).
fof(aHLu_BOOLu_CASES, axiom, ![V_t]: (s(t_bool,V_t) = s(t_bool,t) | s(t_bool,V_t) = s(t_bool,f))).
fof(aHLu_EXT, axiom, ![TV_Q212791,TV_Q212787]: ![V_f, V_g]: (![V_x]: s(TV_Q212787,happ(s(t_fun(TV_Q212791,TV_Q212787),V_f),s(TV_Q212791,V_x))) = s(TV_Q212787,happ(s(t_fun(TV_Q212791,TV_Q212787),V_g),s(TV_Q212791,V_x))) => s(t_fun(TV_Q212791,TV_Q212787),V_f) = s(t_fun(TV_Q212791,TV_Q212787),V_g))).
fof(ah4s_lists_APPENDu_u_equ_u_NILu_c1, axiom, ![TV_u_27a]: ![V_l2, V_l1]: (s(t_h4s_lists_list(TV_u_27a),h4s_lists_append(s(t_h4s_lists_list(TV_u_27a),V_l1),s(t_h4s_lists_list(TV_u_27a),V_l2))) = s(t_h4s_lists_list(TV_u_27a),h4s_lists_nil) <=> (s(t_h4s_lists_list(TV_u_27a),V_l1) = s(t_h4s_lists_list(TV_u_27a),h4s_lists_nil) & s(t_h4s_lists_list(TV_u_27a),V_l2) = s(t_h4s_lists_list(TV_u_27a),h4s_lists_nil)))).
fof(ch4s_strings_STRCATu_u_EQu_u_EMPTY, conjecture, ![V_l2, V_l1]: (s(t_h4s_lists_list(t_h4s_strings_char),h4s_lists_append(s(t_h4s_lists_list(t_h4s_strings_char),V_l1),s(t_h4s_lists_list(t_h4s_strings_char),V_l2))) = s(t_h4s_lists_list(t_h4s_strings_char),h4s_lists_nil) <=> (s(t_h4s_lists_list(t_h4s_strings_char),V_l1) = s(t_h4s_lists_list(t_h4s_strings_char),h4s_lists_nil) & s(t_h4s_lists_list(t_h4s_strings_char),V_l2) = s(t_h4s_lists_list(t_h4s_strings_char),h4s_lists_nil)))).
