let R be the TRS under consideration

active(h(_1)) -> mark(g(_1,_1)) is in elim_R(R)
let r0 be the right-hand side of this rule
p0 = epsilon is a position in r0
we have r0|p0 = mark(g(_1,_1))
mark(g(_2,_3)) -> active(g(mark(_2),_3)) is in R
let l'0 be the left-hand side of this rule
theta0 = {_1/_3, _2/_3} is a mgu of r0|p0 and l'0

==> active(h(_1)) -> active(g(mark(_1),_1)) is in EU_R^1
let r1 be the right-hand side of this rule
p1 = 0 is a position in r1
we have r1|p1 = g(mark(_1),_1)
g(mark(_2),_3) -> g(_2,_3) is in R
let l'1 be the left-hand side of this rule
theta1 = {_1/_3, _2/_3} is a mgu of r1|p1 and l'1

==> active(h(_1)) -> active(g(_1,_1)) is in EU_R^2
let r2 be the right-hand side of this rule
p2 = 0 is a position in r2
we have r2|p2 = g(_1,_1)
g(mark(_2),_3) -> g(_2,_3) is in R
let l'2 be the left-hand side of this rule
theta2 = {_1/mark(_2), _3/mark(_2)} is a mgu of r2|p2 and l'2

==> active(h(mark(_1))) -> active(g(_1,mark(_1))) is in EU_R^3
let r3 be the right-hand side of this rule
p3 = epsilon is a position in r3
we have r3|p3 = active(g(_1,mark(_1)))
active(g(a,_2)) -> mark(f(b,_2)) is in R
let l'3 be the left-hand side of this rule
theta3 = {_1/a, _2/mark(a)} is a mgu of r3|p3 and l'3

==> active(h(mark(a))) -> mark(f(b,mark(a))) is in EU_R^4
let r4 be the right-hand side of this rule
p4 = epsilon is a position in r4
we have r4|p4 = mark(f(b,mark(a)))
mark(f(_1,_2)) -> active(f(mark(_1),_2)) is in R
let l'4 be the left-hand side of this rule
theta4 = {_1/b, _2/mark(a)} is a mgu of r4|p4 and l'4

==> active(h(mark(a))) -> active(f(mark(b),mark(a))) is in EU_R^5
let r5 be the right-hand side of this rule
p5 = 0.1 is a position in r5
we have r5|p5 = mark(a)
mark(a) -> active(a) is in R
let l'5 be the left-hand side of this rule
theta5 = {} is a mgu of r5|p5 and l'5

==> active(h(mark(a))) -> active(f(mark(b),active(a))) is in EU_R^6
let r6 be the right-hand side of this rule
p6 = 0.1 is a position in r6
we have r6|p6 = active(a)
active(a) -> mark(b) is in R
let l'6 be the left-hand side of this rule
theta6 = {} is a mgu of r6|p6 and l'6

==> active(h(mark(a))) -> active(f(mark(b),mark(b))) is in EU_R^7
let r7 be the right-hand side of this rule
p7 = epsilon is a position in r7
we have r7|p7 = active(f(mark(b),mark(b)))
active(f(_1,_1)) -> mark(h(a)) is in R
let l'7 be the left-hand side of this rule
theta7 = {_1/mark(b)} is a mgu of r7|p7 and l'7

==> active(h(mark(a))) -> mark(h(a)) is in EU_R^8
let r8 be the right-hand side of this rule
p8 = epsilon is a position in r8
we have r8|p8 = mark(h(a))
mark(h(_1)) -> active(h(mark(_1))) is in R
let l'8 be the left-hand side of this rule
theta8 = {_1/a} is a mgu of r8|p8 and l'8

==> active(h(mark(a))) -> active(h(mark(a))) is in EU_R^9
let l be the left-hand side and r be the right-hand side of this rule
let p = epsilon
let theta = {}
let theta' = {}
we have r|p = active(h(mark(a))) and
theta'(theta(l)) = theta(r|p)
so, theta(l) = active(h(mark(a))) is non-terminating w.r.t. R

Termination disproved by the forward process
proof stopped at iteration i=9, depth k=3
16437 rule(s) generated