6.5 Pure Maths: Functions
6.30 'Who's Your Teacher, Mum?'
6.55 Evolution of Fishes
7.20 A Woman's Place?
7.45 Design: Assembly of Lorries

The Embassy
World Professional Snooker Championship from the Crucible Theatre, Sheffield
Sixth day
The players had the morning off today but this afternoon round two merges with round one as the championship moves into another gear. TONY KNOWLES (4) will know his first-round fate as he plays the second and last session of ten frames, against Liverpool's new professional JOHN PARROTT. RAY REARDON (2) and TONY MEO (15) were seeded to set out on their second-round match on the next table.
DAVID ICKE introduces live coverage.

Peter Habeler and Reinhold Messner were the first men to climb Everest without oxygen. PETER HABELER tells how and why they did it.
Producer KEN PATTON
A BBC/Open University production

with subtitles, followed by Weather

opens a short season of British film comedies, tonight starring Peter Sellers and Terry-Thomas
When a group of well-known personalities - a television comedian, an authoress, a peer, a glamorous model - are blackmailed by the editor of a scandal sheet, they each decide that he would be better off dead. Unfortunately plans backfire and the quartet decide to gang together...
Peter Sellers is in sparkling form as the many-faceted comedian who is a master of disguise, and the great Wilfred Lawson makes a memorable guest appearance as a Chelsea Pensioner.
Films: page 17

The Embassy World Professional
Snooker Championship, from the Crucible Theatre, Sheffield. Sixth day
This afternoon TONY KNOWLES (4) finished this 19-frame first-round contest, and this evening 'the grinder', CLIFF THORBURN (3), will complete the 16-man second-round line-up.
On the second table tonight STEVE DAVIS (1) was the warmest of favourites to be playing JOHN SPENCER (16) as the best-of-25-frame second-round matches begin.
DAVID VINE has all the details and the latest news from Sheffield.

Sex in the Spring -it's the food they eat that makes some animals amorous at this time of the year. Can we benefit from the latest research?
Hamburgers and the Destruction of Rain forests - what's the connection?
Click - a major photographic competition is launched this week. Heather Angel offers advice. Producer ROBIN HELLIER Editor ANDREW NEAL BBC Bristol
0 FEATURE: page 80

Mike Harding is 'wazzed off', whatever that may mean, in between recounting stories of growing up in tne
Manchester suburb of Crumpsall.
Director JOHN ROONEY ProducerROD TAYLOR BBC Manchester

... of documentary
A series of films portraying issues, institutions and individuals. 0 Alien
A film by David Gladwell
The narrator of this imaginary documentary has invented the idea that tar out in the universe alien beings have heard that here on earth there exists a species which has developed an instinct and a means to destroy itself and its world. An alien arrives to find out what he can about the species. How, the narrator asks, would this world appear to the visitor? bven the grass underfoot would be a new experience. So would a tree, a road, and the high street of a market town. And if the alien who came to earth to witness its end arrived at the town early on a Sunday morning, he would assume he had come too late. There is no sign of life, not a living creature.
But there are bodies without life, behind glass, together with artefacts of all kinds, like Egyptian kings buried with their possessions....
Photography ALEX
HANSEN Radiophonic sound JONATHAN GIBBS Film editor TERENCE TWIGG
Executive producer ROGER MILLS

The Embassy
World Professional Snooker Championship from the Crucible Theatre,
Sheffield STEVE DAVIS and JOHN SPENCER should, according to the formbook, be battling out their second-round match this evening, while CLIFF THORBURN was favourite to be joining them and completing the second-round line-up. DAVID VINE has all the latest news.

John Tusa , Peter Snow and Donald MacCormick , with MAUREEN CARTER and BRIDGET KENDALL , present the reports and interviews that matter with the analysis that counts.

DAVID VINE introduces further coverage from the Crucible Theatre in Sheffield.

12.10 Computing: Top Down Design
How does a computer sort numbers into order? To get a systematic method, you need a systematic design procedure.
12.35 Psychology: Landing an Aircraft
Using the practical problem of landing an aircraft, the programme discusses the cues for the perception of distance, height and speed.