Let us, for a moment, imagine the impossible - a midsummer sports fairy tale of innocence and generosity fair play and community spirit, an oasis of athletic harmony and openhandedness in the inner city.

Imagine a sports league where pros making six-figure salaries participate for free, risking injury in less-than-ideal conditions, simply for the joy of playing.

Imagine that these famous pros - with monikers like Moses (Malone), the Ice Man (George Gervin), David Skywalker (Thompson) and the Truck (Leonard Robinson) - are interspersed with almost equally famous college players - like King Albert (Albert King) and Big Sky (Craig Shelton) - who are anxious to test themselves against the greatest in their game.

And imagine that these are pro and college stars are mixed on the same teams with talented unknowns, those who never made the big time, yet still need a showcase for their skills and their athletic pride.

Naturally, the sign above the entrance gate of this league would say, "The only price of admission is your cooperation."

Small children with scraps of paper for autographs and old man telling tall tales, teen-agers in wheelchairs and hip young ladies in summer dress, black and white squeezed cheerfully together, would crowd the stands to the last free seat.

This seemingly mythical league - The Urban Coalition Summer Basketball League - not only exists in Washington, but flourishes.

Yesterday, on a typical Urban Coalition afternoon, Truck Robinson of the New Orleans Jazz rose for a rebound, then fired to Adrian Dantley of the Los Angeles Lakers, who twisted a layup around Moses Malone of the Houston Rockets.

"Home movies," screamed a fan in the jammed Gonzaga High gym, home of the UCL. "Get out the home movies."

Basketball is the summer game now in this city as well as the winter game. But summer, is the better time for those intimate "home movies" - glimpses of the free-wheeling, gotta-see-it-to-believe-it plays that happen above the rim and beyond belief.

The Urban Coalition's eight-team "pro league" - which includes anybody out of high school who is good enough to hack it - is like a three-month basketball jazz festival, complete with in-your-face workshops to illustrate the riffs you need to improve.

In its eight years of existence, the Urban Coalition League has been a major studio where Julius Erving, George Gervin, David Thompson, Phil Chenier and dozens of other pros have polished their skills.

The Truth about Doctor J, or the Ice Man or Kevin Porter was known to fans who found their way to Urban games long before the NBA got the word.

The whole truth about the UCL, however, goes far beyond consciousness-expanding passes that lead to funkadelic dunks.

Here, far from the cynicism of sports' dollar war, safe from the pomposity of television and telescreen, the celebrity and the street sweeper can be on first-name terms - just fellow basketball art-for-art's sakers grooving on the action.

Bob Ferry, the 6-foot-8 general manager of the NBA champion Washington Bullets, sipped a coke and hobnobbedwith anyone who wanted to chat. John Thompson, 6-11 coach of powerfull Georgetown University, held his tiny daughter Tiffany on his shoulder, leaned on a wall and made himself available to any youngster who wanted to ask about a serious problem or tell a joke.

Perhaps the lion and the lamb do not lie down together here, but the Washington Metros - doormats of the Eastern League - can challenge the Bullet team of reserves and draft choices . . . and win.

The Urban Coalition League has special value because it is not an idyllic fantasy creation, but rather has had to struggle to make a place for itself.

The UCL, unpublicized and unsubisdized, is practically unknown, at least relative to the caliber of its talent. How many fans, glancing at yesterday's UCL schedule of two high school and two pro games knew that the bland entry "Big M Trotters vs. Pappy Parker," really meant Dantley. Robinson and Malone - millions of dollars of NBA talent - spiced with high NBA draft choices Notre Dame's Don Williams and St. Bonaventure's GregSaunders?

Only a couple of thousand fans, out of a city of more than 2 million, attend the free shows. However, they are the inner circle of this city's community of sweat.

When the big names cavort - the "bonafides" as they are called - the crowd is in heaven, debating who is "the best thing on the court."

But woe to him who is not up to scratch. "Get that masked man off the court," hollered a fan after an unknown player shot an air ball.

"Who is that No. 40?" bellowed a disgrunted fan, watching a skinny 6-6 kid playing center for a weak "Bullets" team. "Mitch Kupchak ain't got sick has he? When y'allbringing somereal Bullets down here?

"Brother, I'm about ready to make a move . . . to the door."

It's demanding crowd, considering it gets in free.

"We only ask that you purchase our refreshments and park in our (S2) parking lot so that we can meet expenses," implored the UCL pregame PA announcement.

The force behind this remarkable, firmly established league is Jim Wiggins, 5-7 barber who not only makes no profit from his all-volunteer passion, but dips into his hair-cutting proceeds to make the UCL shoestring stay in one piece.

One glance behind the scenes of the Urban Coalition League is enough to show howhard it is to keep a dream afloat.

According to Wiggins, the D.C. government has never offered any help to this free public recreation that entertains far more than 100,000 people a summer.

"It's an insult to everybody in here to have to sit in an unairconditioned gym in July," said an overheated Thompson, "when there are air-conditioned public facilities, built with our tax dollars, that are empty at this moment."

"Here you've got a perfect example of what community spirit really means. The Gonzaga fathers are letting the teams use their new gym, the Bullets are lending their name and support, and one little barber is running around keeping the whole thing together with his stubborness.

"I'm not pointing my finger at any one person in the city government. I'm pointing at all of them. This league is a beautiful thing. But it's also outrageous."

The fact the UCL's program cannot get support from the city does not faze Wiggins or his volunteer cocommissioner, Arnold George. They keep plugging away, doing what they believe best for their league and city. They are always looking for new tasks.

Since this is the first season the NCAA has allowed pros and current college players to compete together in summer leagues, Wiggins proudly took an all-college Urban Coalition team to Arizona for a tournament in June.

"We won five of six games," said Wiggins, "but I was prouder that our team won the 'best conduct' award. That even includes how neat you keep your hotel rooms."

"Wigs were pretty determined to win that award," said Thompson. "He had those kids out there in the desert - 108 degrees - in coats and ties."

It only sounds like a fairy tale