THE STORIES: EAT CAKE. A biting satire in which a frowzy housewife, absorbed in her TV is visited by an eccentric rapist-whose demands are somewhat different from what might be anticipated. (1 man, 1 woman.) HAROLD. Two doctors examine a patient (played dually by an actor and a dummy) methodically dismembering the dummy to prove that it is in the best of health. (2 men, 1 woman.) TAKE A DEEP BREATH. In this brief, disturbing playlet the victims of air pollution assemble their own mausoleum, while recounting the helpless horror of their demise. (7 men, 1 woman.) PHOTOGRAPHS: MARY AND HOWARD. While their taped voices carry on a random, but revealing, conversation, two people regard each other silently-as still as two photographs. (1 man, 1 woman.) THOUGHTS ON THE INSTANT OF GREETING A FRIEND ON THE STREET. Two people meet by chance, their conversation moving on two levels: one of the idle surface comments the other of deeper thoughts unspoken. (1 man, 1 woman.) THE GIRL AND THE SOLDIER. A girl sings; a soldier speaks of love and war; and a sense of the very nature of our tortured universe is poignantly evoked. (1 man, 1 woman.) ROSARY. A nun, riding home on the subway, says her Rosary-and the depth of her personal anguish is poignantly revealed. (1 woman.)