%   ORIGINAL: 'h4/thm/rich_list/LENGTH_FRONT_'
% 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
% Goal: !l. ~(l = 'h4/const/list/NIL') ==> 'h4/const/list/LENGTH' ('h4/const/list/FRONT' l) = 'h4/const/prim_rec/PRE' ('h4/const/list/LENGTH' l)
%   PROCESSED
% Assm ['HL_TRUTH']: T
% Assm ['HL_FALSITY']: ~F
% Assm ['HL_BOOL_CASES']: !t. (t <=> T) \/ (t <=> F)
% Assm ['HL_EXT']: !f g. (!x. happ f x = happ g x) ==> f = g
% Goal: !l. ~(l = 'h4/const/list/NIL') ==> 'h4/const/list/LENGTH' ('h4/const/list/FRONT' l) = 'h4/const/prim_rec/PRE' ('h4/const/list/LENGTH' l)
fof('HL_TRUTH', axiom, p(s(bool,'T'))).
fof('HL_FALSITY', axiom, ~ (p(s(bool,'F')))).
fof('HL_BOOL_CASES', axiom, ![T]: (s(bool,T) = s(bool,'T') | s(bool,T) = s(bool,'F'))).
fof('HL_EXT', axiom, ![V_3f55161,V_3f55157]: ![F, G]: (![X]: s(V_3f55157,happ(s(fun(V_3f55161,V_3f55157),F),s(V_3f55161,X))) = s(V_3f55157,happ(s(fun(V_3f55161,V_3f55157),G),s(V_3f55161,X))) => s(fun(V_3f55161,V_3f55157),F) = s(fun(V_3f55161,V_3f55157),G))).
fof('h4/thm/rich_list/LENGTH_FRONT_', conjecture, ![A]: ![L]: (~ (s('h4/type/list/list'(A),L) = s('h4/type/list/list'(A),'h4/const/list/NIL')) => s('h4/type/num/num','h4/const/list/LENGTH'(s('h4/type/list/list'(A),'h4/const/list/FRONT'(s('h4/type/list/list'(A),L))))) = s('h4/type/num/num','h4/const/prim_rec/PRE'(s('h4/type/num/num','h4/const/list/LENGTH'(s('h4/type/list/list'(A),L))))))).
