2007 IMO Shortlist Problems/A2
Problem
(Bulgaria)
Consider those functions 
which satisfy the condition
\[f(m+n)\ge f(m)+f(f(n))−1\] (Error compiling LaTeX. Unknown error_msg)
for all 
, 
\in\mathbb{N}
f(2007)
\mathbb{N}$ denotes the set of all positive integers.)
