Consider the TRS R consisting of the rewrite rules 1: 0(#) -> # 2: # + x -> x 3: x + # -> x 4: 0(x) + 0(y) -> 0(x + y) 5: 0(x) + 1(y) -> 1(x + y) 6: 1(x) + 0(y) -> 1(x + y) 7: 1(x) + 1(y) -> 0((x + y) + 1(#)) 8: (x + y) + z -> x + (y + z) 9: # - x -> # 10: x - # -> x 11: 0(x) - 0(y) -> 0(x - y) 12: 0(x) - 1(y) -> 1((x - y) - 1(#)) 13: 1(x) - 0(y) -> 1(x - y) 14: 1(x) - 1(y) -> 0(x - y) 15: not(true) -> false 16: not(false) -> true 17: if(true,x,y) -> x 18: if(false,x,y) -> y 19: ge(0(x),0(y)) -> ge(x,y) 20: ge(0(x),1(y)) -> not(ge(y,x)) 21: ge(1(x),0(y)) -> ge(x,y) 22: ge(1(x),1(y)) -> ge(x,y) 23: ge(x,#) -> true 24: ge(#,0(x)) -> ge(#,x) 25: ge(#,1(x)) -> false 26: log(x) -> log'(x) - 1(#) 27: log'(#) -> # 28: log'(1(x)) -> log'(x) + 1(#) 29: log'(0(x)) -> if(ge(x,1(#)),log'(x) + 1(#),#) There are 30 dependency pairs: 30: 0(x) +# 0(y) -> 0#(x + y) 31: 0(x) +# 0(y) -> x +# y 32: 0(x) +# 1(y) -> x +# y 33: 1(x) +# 0(y) -> x +# y 34: 1(x) +# 1(y) -> 0#((x + y) + 1(#)) 35: 1(x) +# 1(y) -> (x + y) +# 1(#) 36: 1(x) +# 1(y) -> x +# y 37: (x + y) +# z -> x +# (y + z) 38: (x + y) +# z -> y +# z 39: 0(x) -# 0(y) -> 0#(x - y) 40: 0(x) -# 0(y) -> x -# y 41: 0(x) -# 1(y) -> (x - y) -# 1(#) 42: 0(x) -# 1(y) -> x -# y 43: 1(x) -# 0(y) -> x -# y 44: 1(x) -# 1(y) -> 0#(x - y) 45: 1(x) -# 1(y) -> x -# y 46: GE(0(x),0(y)) -> GE(x,y) 47: GE(0(x),1(y)) -> NOT(ge(y,x)) 48: GE(0(x),1(y)) -> GE(y,x) 49: GE(1(x),0(y)) -> GE(x,y) 50: GE(1(x),1(y)) -> GE(x,y) 51: GE(#,0(x)) -> GE(#,x) 52: LOG(x) -> log'(x) -# 1(#) 53: LOG(x) -> LOG'(x) 54: LOG'(1(x)) -> log'(x) +# 1(#) 55: LOG'(1(x)) -> LOG'(x) 56: LOG'(0(x)) -> IF(ge(x,1(#)),log'(x) + 1(#),#) 57: LOG'(0(x)) -> GE(x,1(#)) 58: LOG'(0(x)) -> log'(x) +# 1(#) 59: LOG'(0(x)) -> LOG'(x) The approximated dependency graph contains 5 SCCs: {51}, {31-33,35-38}, {40-43,45}, {46,48-50} and {55,59}. - Consider the SCC {51}. There are no usable rules. By taking the polynomial interpretation [#] = 1, [0](x) = x + 1 and [GE](x,y) = x + y + 1, rule 51 is strictly decreasing. - Consider the SCC {31-33,35-38}. The usable rules are {1-8}. By taking the polynomial interpretation [#] = 0, [0](x) = x, [1](x) = x + 1 and [+](x,y) = [+#](x,y) = x + y + 1, the rules in {1,4-8,31,35,37} are weakly decreasing and the rules in {2,3,32,33,36,38} are strictly decreasing. There is one new SCC. - Consider the SCC {31,35,37}. By taking the polynomial interpretation [#] = 0, [0](x) = [1](x) = x + 1, [+](x,y) = x + y and [+#](x,y) = x + y + 1, the rules in {2,3,7,8,37} are weakly decreasing and the rules in {1,4-6,31,35} are strictly decreasing. There is one new SCC. - Consider the SCC {37}. By taking the polynomial interpretation [#] = 0, [0](x) = x, [+#](x,y) = [1](x) = x + 1 and [+](x,y) = x + y + 1, the rules in {1,4-8} are weakly decreasing and the rules in {2,3,37} are strictly decreasing. - Consider the SCC {40-43,45}. The usable rules are {1,9-14}. By taking the polynomial interpretation [#] = 0, [0](x) = [1](x) = x + 1, [-](x,y) = x + y and [-#](x,y) = x + y + 1, the rules in {9,10,12} are weakly decreasing and the rules in {1,11,13,14,40-43,45} are strictly decreasing. - Consider the SCC {46,48-50}. There are no usable rules. By taking the polynomial interpretation [0](x) = [1](x) = x + 1 and [GE](x,y) = x + y + 1, the rules in {46,48-50} are strictly decreasing. - Consider the SCC {55,59}. There are no usable rules. By taking the polynomial interpretation [0](x) = [1](x) = [LOG'](x) = x + 1, the rules in {55,59} are strictly decreasing. Hence the TRS is terminating.