English
If hc: 1 < c, hb: c ≤ b, hm n ≤ m, then clog_b m ≤ clog_c n.
Русский
Если 1 < c, c ≤ b и m ≤ n, то clog_b m ≤ clog_c n.
LaTeX
$$$ (1 < c) \\land (c \\le b) \\land (m \\le n) \\implies \\operatorname{clog}_b m \\le \\operatorname{clog}_c n $$$
Lean4
@[mono, gcongr]
theorem clog_mono {b c m n : ℕ} (hc : 1 < c) (hb : c ≤ b) (hmn : m ≤ n) : clog b m ≤ clog c n :=
(clog_anti_left hc hb).trans <| by gcongr