6.35 Light on Lasers
7.00 Blancmanges and Snowflakes what is meant by well-behaved function? And what is the mathematical link between blancmanges and mountain ranges, or snowflakes and coastlines?

With Philippa Forrester. ● STEREO
More puppet fun in the town of Spencerville, with a warm welcome from its mayor, the worst dresser in the world, Mr Hallo Spencer.

Animated tales of the elephant king, based on the famous children's books.
Babar chooses Arthur to be his partner in the annual bike race. However, he soon begins to feel he should have chosen someone a little more athletic.

Canine adventure series.
The McCulloch family is in danger of losing Lassie when a woman from Uncle Steve's past arrives and claims the dog belongs to her.

Space-age cartoon fun.
Jane's wedding anniversary plans go awry when she discovers that her marriage to George was never legal.

Today's show features fast-moving ice hockey action with a preview of the excitement to come when the Montreal Canadians face the Chicago Blackhawks at Wembley next week. There's a film showing what happened at a special "clinic" for young players that some of the players held at Alexandra Palace in north London on a recent visit to Britain.

There's another round of the new backwards game Parallel Playback, some backwards talking, cartoon action with Swamp Thing and the latest video reviews. Meanwhile, the alien Prince Mercator is still stuck on Parallel 9, the white hole in outer space where he has been banished for seeking knowledge and asking for change on a planet where such things are forbidden. His fellow exiles, the three villains Steyl, Skyn and Thynkso, and earth-girl Cal, are still trying to amass enough knowledge to be able to escape.

With Roddy Maude-Roxby, Helen Atkins, Jenny Bolt, Dominic McHale and Kevin Williams.

A Roach production for BBCtv
(Stereo)
Earth-Knowledge: If you want to send a message to Mercator. write to P9, [address removed]

Introduced by Steve Rider.
Provisional Timetable
10.20 Cricket; 12.45 Football
1.00 News; 1.05 Football
1.25 Cricket; 1.55 Racing
2.05 Cricket; 2.25 Racing
2.35 Cricket; 3.25 Racing
3.35 Cricket
3.50 Football half-times
4.00 Cricket
4.40 Final Score

Cricket
Live coverage of the NatWest Bank Trophy final from Lord's.
Leicestershire v Northamptonshire
Leicestershire are in their first end-of-season Lord's final against five-times finalists Northants. Leicestershire last appeared at Lord's in 1985 in the Benson and Hedges Cup final when they defeated Essex. Their three other appearances at Lord's came between 1972 and 1975 in the same competition, when they were victorious twice. Now they hope to emulate Hampshire who won on their maiden visit to a NatWest final last year. Northamptonshire have won only two of their seven Lord's finals. They won this trophy when it was still the Gillette Cup, beating Lancashire in 1976, and also have a 1980 Benson and Hedges success to their credit. But they have lost their last four NatWest/Gillette finals. Captain Allan Lamb will be hoping for a change in fortune today.
(Coverage continues at 4.30pm on BBC2)
Sport: page 14

Football Focus
Bob Wilson and Gary Lineker with the latest action, news and views on the Premier League. Plus the usual comprehensive results service and pools check in Final Score.

Racing
From Haydock.
2.00 Ladbroke Handicap (7f)
2.30 Webster's Yorkshire Bitter Stakes (1m 2f 120yds)
3.30 Haydock Park Sprint Cup (6f). The last major Group 1 sprint of the British season.
With commentary by Jimmy Lindley, Peter O'Sullevan and Julian Wilson.

This compilation of some of the best moments from past programmes sets the scene for a new series that starts soon.
In between doing their best to get fit for future games, Bruce Forsyth and Rosemarie Ford take time to look back and remember Bob Merson , Janice Perkins and Lynn and Steve Powell attempting to become one-man bands, and a very special lesson in bed-making from Big Break's Jim Davidson and John Virgo. Producer David Taylor ● STEREO
* TELETEXT SUBTITLES: page 888

People will believe the most ludicrous stories, as impressionist and comic
Bobby Davro discovers in this family entertainment series.
He has been hiding TV cameras in the sneakiest of places to capture the unsuspecting
British public as they fall for some ridiculous practical jokes. But the celebrities on the show get an even rougher ride: this week, for example,
Keith Chegwin lives to regret the balloon dance he once did for charity, and there's a chance to see quizmaster Bob Holness adding sincerity to an advertisement for shampoo.
Former-model Linda Lusardi is caught looking distinctly unglamorous and comedian
Paul Shane sees a hip-thrusting rendition of It's Not Unusual that he would rather forget. Series producer Brian Wesley Editor Judith Holder
STEREO
● TELETEXT SUBTITLES: page 888 0 FEATURE: page 26

A special screening of the most successful film of all time, starring Henry Thomas, Dee Wallace, Peter Coyote
When an alien spacecraft lands in a suburb of Los Angeles, its personnel are interrupted in their search of the surrounding woods by a group of men who seem to be looking for them. Forced to make a hurried departure, they inadvertently leave behind one of their number who takes shelter in the back garden of the nearest house. Suddenly, 10-year-old Elliott has a new friend - he's short, dark and from another planet and nobody must know he's here.
Despite communication problems their friendship develops, but the alien cannot survive on earth for long. He needs to "phone home" to be rescued. Steven Spielberg's famous adventure mixes laughter and tears, thrills and special effects for perfect family entertainment. Watch out for a brief appearance by glamorous Baywatch star Erika Eleniak.
STEREO
TELETEXT SUBTITLES: page 888
FILMS: pages 33-39

Jasper Carrott reviews some of the world's weirdest, wildest and most outrageous television advertisements, and discovers why dogs sometimes wear gas masks and what Bjorn Borg 's underpants are like.
He also takes a nostalgic look at some black and white commercials from the 50s, including a particular favourite featuring a knight in shining armour who gives cash to householders merely for being able to produce a box of the right kind of soap powder. Director/Producer Paul Smith
A Celador production for BBCtv STEREO
● TELETEXT SUBTITLES: page 888

With Martyn Lewis.
Weather Peter Cockroft
0 TELETEXT SUBTITLES (news): page 888

Extended highlights of two of this afternoon's fixtures in the new Premier League, plus the key action and reaction from the remaining seven fixtures. With expert analysis in the studio from former Liverpool captain Alan Hansen , reports from Ray Stubbs and Clive Tyldesley , and match commentary by Barry Davies and John Motson.
Introduced by Desmond Lynam. Series producer John Shrewsbury Editor Brian Barwick
• STEREO

Disaster film starring George Segal
Richard Widmark
Timothy Bottoms
A rollercoaster crash and a fire at a fun fair appear to be coincidences but safety inspector Harry Calder suspects that someone is trying to sabotage the rides. Can he solve the mystery in time to prevent the killer from springing a further rollercoaster death trap?
Director James Gold stone
● TELETEXT SUBTITLES: page 888 • FILMS: pages 33-39