YES

TRS:

  msort(nil()) -> nil()
  msort(.(x,y)) -> .(min(x,y),msort(del(min(x,y),.(x,y))))
  min(x,nil()) -> x
  min(x,.(y,z)) -> if(<=(x,y),min(x,z),min(y,z))
  del(x,nil()) -> nil()
  del(x,.(y,z)) -> if(=(x,y),z,.(y,del(x,z)))

max/plus interpretations on N:

  msort_A(x1) = max{8, 7 + x1}
  msort#_A(x1) = max{4, 7 + x1}
  nil_A = 9
  nil#_A = 5
  ._A(x1,x2) = max{14, -2, 4 + x2}
  .#_A(x1,x2) = max{0, 1, 1}
  min_A(x1,x2) = max{9, 2 + x1, 4 + x2}
  min#_A(x1,x2) = max{12, 10, 9 + x2}
  del_A(x1,x2) = max{1, -6, 10}
  del#_A(x1,x2) = max{1, 3, 3}
  if_A(x1,x2,x3) = max{10, -6, 9, 2}
  if#_A(x1,x2,x3) = max{3, 0, 0, 3}
  <=_A(x1,x2) = max{1, 1 + x1, 1 + x2}
  <=#_A(x1,x2) = max{11, 6, 6}
  =_A(x1,x2) = max{1, 1 + x1, 1 + x2}
  =#_A(x1,x2) = max{2, 0, 0}

precedence:

  del > msort = <= = = > nil = min > . = if