problem([]==>x:pnat=>less(x,s(x)),
ind_strat(induction(lemma(pnat_primitive)-[(x:pnat)-s(v0)])then[base_case(sym_eval(normalize_term([reduction([],[less2,equ(u(1),left)])]))then[elementary(istrue)]),step_case(ripple(direction_out,unblock_then_wave(direction_out,unblock_lazy([unblock(meta_ripple,unused,unused),idtac])then wave(direction_out,[],[less3,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,[less2 of 0],[v0]),[term_of(less2)],[less2]),[v0,v1,su(su(su(v1,[v2 of s(v0)],[v3]),[less3 of v0],[v2]),[term_of(less3)],[less3])])),
[
]).
