Prologue: a view from 1988 -- Algebraic theory of linear parallel predicates: Theory of linear Boolean inequalities ; Group invariance of Boolean inequalities ; Parity and one-in-a-box predicates ; The "and/or" theorem -- Geometric theory of linear inequalities: [Psi]connected: a geometric property with unbounded order ; Geometric patterns of small order: spectra and context ; Stratification and normalization ; The diameter-limited perception ; Geometric predicates and serial algorithms -- Learning theory: Magnitude of the coefficients ; Learning ; Linear separation and learning ; Perceptions and pattern recognition -- Epilogue: the new connectionism.