YES

# strong closedness (Huet 1980)

Consider the left-linear TRS R:

  b(a(b(b(x)))) -> b(b(b(a(b(x)))))
  b(a(a(b(b(x))))) -> b(a(b(b(a(a(b(x)))))))
  b(a(a(a(b(b(x)))))) -> b(a(a(b(b(a(a(a(b(x)))))))))

R is linear and every critical pair is strongly closed