problem([]==>x:pnat=>leq(x,x),
ind_strat(induction(lemma(pnat_primitive)-[(x:pnat)-s(v0)])then[base_case(sym_eval(normalize_term([reduction([],[leq1,equ(u(1),left)])]))then[elementary(istrue)]),step_case(ripple(direction_out,wave(direction_out,[],[leq3,equ(u(1),left)],[]))then[unblock_then_fertilize(strong,unblock_fertilize_lazy([idtac])then fertilize(strong,v1))])]),lambda(x,p_ind(x,su(su(0,[leq1 of 0],[v0]),[term_of(leq1)],[leq1]),[v0,v1,su(su(su(v1,[v2 of v0],[v3]),[leq3 of v0],[v2]),[term_of(leq3)],[leq3])])),
[
]).
