problem([]==>a:u(1)=>b:u(1)=>c:u(1)=>d:u(1)=> (((a=>c)#b=>c)=>d)=> ((a\b)=>c)=>d,
repeat dequantify_once,lambda(a,lambda(b,lambda(c,lambda(d,_8854)))),
[problem([a:u(1),b:u(1),c:u(1),d:u(1)]==> (((a=>c)#b=>c)=>d)=> ((a\b)=>c)=>d,
 propositional,lambda(v0,lambda(v1,su(v2,[v0 of (lambda(v2,su(su(v4,[v1 of inl(v2)],[v4]),[v0 of su(lambda(v4,v3)&lambda(v4,v3),[v1 of inl(v2)],[v3])],[v3]))&lambda(v2,su(su(v4,[v1 of inr(v2)],[v4]),[v0 of su(lambda(v4,v3)&lambda(v4,v3),[v1 of inr(v2)],[v3])],[v3])))],[v2]))),
 [
 ]) ext _8854
]).
