problem([]==>x:pnat=>x<*0=>void,
intro,lambda(x,_8685),
[problem([x:pnat]==>x<*0=>void,
 elim(x),p_ind(x,_8714,[v0,v1,_8720]),
 [problem([x:pnat]==>0<*0=>void,
  apply(arith(<*))then wfftacs,lambda(v0,v0),
  [
  ]) ext _8714,
  problem([x:pnat,v0:pnat,v1:v0<*0=>void]==>s(v0)<*0=>void,
  apply(arith(<*))then wfftacs,lambda(v2,v2),
  [
  ]) ext _8720
 ]) ext _8685,
 problem([]==>pnat in u(1),
 repeat wfftac,axiom,
 [
 ])
]).
