YES

We show the termination of the relative TRS R/S:

  R:
  f(s(x),y,y) -> f(y,x,s(x))

  S:
  rand(x) -> x
  rand(x) -> rand(s(x))

-- SCC decomposition.

Consider the non-minimal dependency pair problem (P, R), where P consists of

p1: f#(s(x),y,y) -> f#(y,x,s(x))

and R consists of:

r1: f(s(x),y,y) -> f(y,x,s(x))
r2: rand(x) -> x
r3: rand(x) -> rand(s(x))

The estimated dependency graph contains the following SCCs:

  {p1}


-- Reduction pair.

Consider the non-minimal dependency pair problem (P, R), where P consists of

p1: f#(s(x),y,y) -> f#(y,x,s(x))

and R consists of:

r1: f(s(x),y,y) -> f(y,x,s(x))
r2: rand(x) -> x
r3: rand(x) -> rand(s(x))

The set of usable rules consists of

  r1, r2, r3

Take the reduction pair:

  lexicographic combination of reduction pairs:
  
    1. weighted path order
    
      base order:
    
        matrix interpretations:
        
          carrier: N^2
          order: standard order
          interpretations:
            f#_A(x1,x2,x3) = ((1,0),(1,1)) x1 + ((1,0),(0,0)) x2 + ((0,0),(1,1)) x3 + (1,1)
            s_A(x1) = x1
            f_A(x1,x2,x3) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x3 + (1,1)
            rand_A(x1) = ((1,0),(1,1)) x1 + (1,1)
    
      precedence:
      
        f# = s = f = rand
      
      partial status:
    
        pi(f#) = []
        pi(s) = []
        pi(f) = []
        pi(rand) = []
    
    2. weighted path order
    
      base order:
    
        matrix interpretations:
        
          carrier: N^2
          order: standard order
          interpretations:
            f#_A(x1,x2,x3) = ((0,1),(0,0)) x1 + ((0,1),(0,0)) x2 + (2,1)
            s_A(x1) = ((0,0),(1,1)) x1 + (1,2)
            f_A(x1,x2,x3) = ((0,0),(0,1)) x1 + ((0,0),(0,1)) x3 + (2,1)
            rand_A(x1) = (0,0)
    
      precedence:
      
        s = f > f# > rand
      
      partial status:
    
        pi(f#) = []
        pi(s) = []
        pi(f) = []
        pi(rand) = []
    

The next rules are strictly ordered:

  p1

We remove them from the problem.  Then no dependency pair remains.