Abs sub const bmo le two
DeGiorgi.abs_sub_const_bmo_le_two
Plain-language statement
The absolute value function |u - c| has BMO seminorm at most 2M whenever u has BMO seminorm at most M. Uses the reverse triangle inequality ||a| - |b|| ≤ |a - b|.
Source project: DeGiorgi
Person-level attribution pending.