MAYBE
* Step 1: Failure MAYBE
  + Considered Problem:
      - Strict TRS:
          a() -> b()
          a() -> c()
          gcd(x,y) -> gcd2(x,y,0())
          gcd2(x,y,i) -> if1(le(x,0()),le(y,0()),le(x,y),le(y,x),x,y,inc(i))
          if1(false(),b1,b2,b3,x,y,i) -> if2(b1,b2,b3,x,y,i)
          if1(true(),b1,b2,b3,x,y,i) -> pair(result(y),neededIterations(i))
          if2(false(),b2,b3,x,y,i) -> if3(b2,b3,x,y,i)
          if2(true(),b2,b3,x,y,i) -> pair(result(x),neededIterations(i))
          if3(false(),b3,x,y,i) -> gcd2(minus(x,y),y,i)
          if3(true(),b3,x,y,i) -> if4(b3,x,y,i)
          if4(false(),x,y,i) -> gcd2(x,minus(y,x),i)
          if4(true(),x,y,i) -> pair(result(x),neededIterations(i))
          inc(0()) -> 0()
          inc(s(i)) -> s(inc(i))
          le(0(),y) -> true()
          le(s(x),0()) -> false()
          le(s(x),s(y)) -> le(x,y)
          minus(x,0()) -> x
          minus(0(),y) -> 0()
          minus(s(x),s(y)) -> minus(x,y)
      - Signature:
          {a/0,gcd/2,gcd2/3,if1/7,if2/6,if3/5,if4/4,inc/1,le/2,minus/2} / {0/0,b/0,c/0,false/0,neededIterations/1
          ,pair/2,result/1,s/1,true/0}
      - Obligation:
          innermost runtime complexity wrt. defined symbols {a,gcd,gcd2,if1,if2,if3,if4,inc,le
          ,minus} and constructors {0,b,c,false,neededIterations,pair,result,s,true}
  + Applied Processor:
      NaturalPI {shape = Mixed 3, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
  + Details:
      Incompatible
MAYBE