THE RATE OF CHANGE OF THE RATE OF CHANGE. WHATEVER. I wish business types would understand a little calculus. Destination: Freedom links to an interview with the president of the Genesee and Wyoming Railroad, expecting better times for short lines.

A renaissance -- that's what Mortimer Fuller, chief executive officer of Genesee & Wyoming, the Greenwich-based owner and operator of regional and short-line railroads, is hoping for in the rail industry.

For many decades, railroads have been on the decline, losing share to the highway system and trucks. Fuller, however, believes the industry has an opportunity to get back on track.

"We are at an inflection point," Fuller said. "All the factors just might be in place to win back share from trucks."

Umm, no, that's a critical point, making a transition from losing share to trucks to gaining share from trucks. The second derivative is positive throughout. The inflection point will come as rail continues to gain share from trucks, but at a diminishing rate. The second derivative changes sign from positive to negative. Not there yet. Sometimes it's better to use the usual business jargon and sound unimaginative, e.g. "lots of upside potential," rather than to lapse into bad mathematics and sound foolish.