προβλήματα, from προβάλλω, I put forward), a question proposed. In logic, a proposition that appears neither absolutely true nor absolutely false; and consequently may be asserted either in the affirmative or negative. In geometry, a proposition in which some operation or construction is required; as to divide a line or an angle, let fall a perpendicular, &c. In general, any question involving doubt or uncertainty, and requiring further evidence for its solution.