def fibs(n, m):
a = b = <NUM_LIT:1><EOL>for x in range(<NUM_LIT:3>, m + <NUM_LIT:1>):<EOL><INDENT>a, b = b, a + b<EOL>if x >= n:<EOL><INDENT>yield b<EOL><DEDENT><DEDENT>
Yields Fibonacci numbers starting from ``n`` and ending at ``m``.