YES

# almost development closedness (van Oostrom 1997)

Consider the left-linear TRS R:

  +(0(),y) -> y
  +(x,0()) -> x
  +(s(x),y) -> s(+(x,y))
  +(x,s(y)) -> s(+(x,y))
  +(x,y) -> +(y,x)

R is left-linear and every critical pair is almost development closed