ring
a b c d : ℝ
ha : 0 < a
hb : 0 < b
hc : 0 < c
hd : 0 < d
h3 : a / (a + b + d) < a / (a + b)
h4 : b / (a + b + c) < b / (a + b)
h5 : c / (b + c + d) < c / (c + d)
h6 : d / (a + c + d) < d / (c + d)
⊢ c + d + c + d = 2 * (c + d)
no goals