CHAPTER 5 JULY                                              Rosa's home was called ‘Fairways’ and it was half way to Kilmalcolm, a low ranch-style house sitting on a small loop road off the Kilmalcolm Road facing fields with cows and a few mature sycamores. It backed on to the Sandyhills Golf Course within easy range of a deviant tee-shot at the sixteenth.          Rosa joked about that. She said that when they sat out on the lawn on a summer's afternoon, they handed round tin hats with the cucumber sandwiches. He asked her about her husband but all she would say was ‘Maurice is in business.’          Allan watched her as she drove. Yellow blouse open at the neck contrasting with her black hair. Short sleeves. Olive brown arms. Small hands on the wheel. She sat upright, concentrating uneasily on the road ahead as though she wanted to be doing something else. She joked but there was no happiness in her laughter.          There was no one in the house when they arrived. Rosa sat him down by the fireplace in a huge open-plan room - was it a room? With lots of glass and chromium it had the flavour of executive lounge about it. If a loud speaker had announced the departure of flight 405 it would not have seemed surprising. There was a tidy pile of logs but no flames in the fireplace. Beyond a bar-counter and a raised step there was the gleam of copper kitchenwear and polished pine worktops. Rosa put an apron on over her skirt and blouse and began straight away to deal with the stuff she had brought in with her. Plates rattled. The microwave hummed. She was apologetic, shouting across to him as she worked, ‘I hope you don't mind frozen ... It's all I could get ... for speed you know ... Maurice puts me to shame.’ She laughed nervously. ‘He's such a gourmet.’          Maurice appeared at that moment, heavily built, balding, red face, bushy sideburns.          ‘How do you do,’ he said from across the room when Rosa introduced Allan but his attention was on the worktop where Rosa had dumped her purchases. He held up a packet and read what it said on the side with distaste. Then he put it down and said ‘Extraordinary!’ and left the room.          He came back later when they were sitting at a pine kitchen-style table eating de-frozen savoury pancakes with pecan sauce. It was not bad. Allan, doing the polite thing, said how nice it was. Maurice poked it uncertainly with a fork and then said ‘I think this needs some wine.’ He went off again and returned with a bottle of Burgundy. He was a bit huffy when Allan said his no thank you.          Maurice gave them a lecture on the wine. He had bought it at some ‘cave’ in France and went into minute detail of how he had found it, and the way he had struck the bargain. Allan asked him about his work and made the mistake of calling him ‘Professor Telman’.          ‘Watson actually,’ Maurice said without looking up. Then he looked at Rosa and said. ‘Rosa has done the feminist thing with her name you see.’          He had been a Professor of Accountancy now he was on the boards of half a dozen companies. But he was still a professor, and Allan and Rosa were his students. He gave them another lecture, this time on business management, on the absurdity of Trade Union leaders and on the need for ‘Stability’ and ‘Business Confidence’. Those words again. Allan smiled inwardly. Pious words to Maurice and his kind - invective to Jean and her SNP friends.          The monologue was interrupted at that point. There was a roar of a car with no silencer, a pattering of gravel against the front of the house and a leitmotiv played fortissimo on the accelerator pedal.          ‘Bob,’ said Rosa.          The door burst open and a young man and woman came in accompanied by a blare of pop music. The young man wore a bomber jacket. The girl had green hair and carried a ghetto-blaster in her hand. Rosa made hand signals to her to cut the music which for a while the green-haired girl pretended to misunderstand, briefly turning it louder. Then for half an hour these two, Bob and Julia Watson, Maurice's children, Rosa's step-children, created a maelstrom. They weren't much younger than Allan but somehow he felt a generation apart.          ‘Is this all we've got?’ Julia said standing with the fridge door open with her hip cocked to one side. Cupboard doors were banged. The microwave hummed again.          Allan was fascinated by the way Rosa reacted. At work she was so self-assured. Everyone deferred to her judgement. Here, no one gave a damn about her and she behaved like a nervous child, hesitant, trying vainly to put in a word here and there. The crease between her eyebrows deepened. She introduced Allan. Bob said ‘Hi!’ and went on putting slices of ham into a roll. Julia ignored him and said to Maurice ‘We're going out.’ And they did shortly afterwards with another concerto on the accelerator pedal, leaving the ghetto-blaster blaring somewhere in the house. Rosa went looking for it and switched it off.          Soon afterwards Maurice went to meet a friend at the golf clubhouse. Rosa relaxed, settling down like a leaf after the passage of of a whirlwind.          ‘Do you never drink?’ she said.          ‘No never. I'm not a reformed alcoholic.’          ‘I'm sorry. I didn't mean ...’ She was straightening things out, tidying away dirty dishes, getting a bowl of trifle out of the fridge, putting the coffee on to perk, just the two of them again on opposite sides of the table.          ‘Let's go into the garden,’ she said. ‘It's getting dark so there will be a cease-fire with the golfers until morning. I just hope no-one ever invents luminous golf-balls.’          It was dusk and the coffee was good. A blackbird was still warbling.          Rosa asked him about his home and he told her about Uncle Roddy and Jean. She said ‘It's not been very exciting for you since you came. I'm sorry. I didn't meant to involve you in the testing software. I really intended to let you carry on with your work on correctness theory. How do you feel about it so far?’          Allan protested politely and truthfully - he understood completely, and dishonestly - he was perfectly happy.          ‘I wondered,’ she leaned back in her chair. Even in the darkling he could see she was smiling. ‘I wondered if you would like to help me with a small project.’          ‘What kind of project?’          ‘More or less the work we both want to do.’ She put her cup down and folded her hands in her lap. ‘You see now that MCI have taken it away from us, there is no chance that we can get into that work officially, but there is nothing to stop us doing a little bit of work on our own.’          ‘Would they know at MCI?’          ‘Not if we didn't tell them.’          She was full of surprises. But sister Jean's influence was strong. He tested the idea for hidden trapdoors. The blackbird had stopped. Some other bird was singing more quietly in the stillness.          ‘What would it involve exactly?’          ‘Well ...’ She was thinking as she spoke. ‘I thought that we might work together on the idea in our spare time. I could make sure that you were not given too much at work so that you would have some spare time. We could work in the evenings and exchange notes during the day.’          ‘But what would the project be?’          She offered him more coffee from the pot but he declined. She poured more for herself then sat back again, holding the cup in her lap.          ‘More or less what we originally intended. We could prove the correctness of the new Labyrinth operating system - no deadlocks, no unfairness, no starvation.’          These were the technical terms for a well behaved operating system that gave all users a proper share of resources. But he was puzzled.          ‘But I thought that that problem was being given to the Olafsen team. Are we going to be given the source code?’          Proofs were done on source code. Without that you were high and dry.          ‘Ah. Well. You see that is the difficult bit. But there is a way round it.’ A gleam of light from the darkening sky was reflected in her eye. She leaned forwards and put her hands together as though praying, thumbs just under her chin. ‘You see .... I think we can do it on the machine code.’          No one did that. The machine code was a hideous jumble of instructions. Some of the code was even ambiguous. But he didn't protest. He knew that she knew that. There had to be a catch. He took a deep breath.          She said, ‘I'm not mad Allan. It can be done. You see the order code for the Labyrinth is structured and it's orthogonal. It doesn't have the same problems as other order codes.’          He stretched and clasped his hands behind his head, frowning, doubting, but all ears.          He said, ‘Supposing we could do this. How could we tell anyone let alone publish?’          ‘We'd find a way. Through some of your university friends perhaps.’          He couldn't quite see that but wondered if it mattered. They wouldn't succeed anyway. Of that he was sure. But trying might be good fun. Better than the stuff he was doing and it would keep him active in the field while he looked around for something else.          Rosa spoke again. ‘There's something else Allan. If we managed to find an automatic proof method for the operating system there is no reason why we could not do the same for any program running on the Labyrinth.’          He spluttered. ‘Oh come on!’          ‘I'm serious Allan. The programs are in the same machine code.’          ‘But you've got no specification for what the programs are trying to do!’          You needed a spec. There was no other way the proof system could know what the program was supposed to do and therefore no way to prove that it was doing it.          ‘For most programs perhaps. But for some we could write the spec ourselves. The important thing is to prove that it is possible.’          ‘A spec in machine code!’          ‘No. In logic notation. We would have to find a way to resolve the variables.’          She was mad - or was she? He finished his coffee, which was cold, keeping the cup up to his lips between sips while he thought.          She said ‘More?’          He shook his head and put the cup down. The fun thing was to try. Success was relatively unimportant to him. Getting back into it, into the literature, running back through the logic expressions again. Something would come out of it even if it wasn't the impossible objective Rosa was setting for them.          ‘Ok,’ he said. ‘I give it a try.’          It was really dark now but somehow he knew she was beaming at him.