MAYBE

'Pop* with parameter subtitution (timeout of 60.0 seconds)'
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Answer:           MAYBE
Input Problem:    innermost relative runtime-complexity with respect to
  Strict Rules: {f(el(x), y) -> f(x, el(y))}
  Weak Rules:
    {  f(x, y) -> f(l(x), y)
     , f(x, y) -> f(x, r(y))
     , l(el(x)) -> el(l(x))
     , el(r(x)) -> r(el(x))}

Proof Output:    
  The input cannot be shown compatible