Set theory Logic, Symbolic and mathematical 11 Fuzzy sets 6 Control theory 5 Infinite 5 Mathematics 5 Problems, exercises, etc 5 Proof theory 5 Computer logic 4 Model theory 4 Outlines, syllabi, etc 4 Recursion theory 4 Cardinal numbers 3 Engineering mathematics 3 Mathematical analysis 3 Multiple comparisons (Statistics) 3 Nonlinear control theory 3 Philosophy 3 Rough sets 3 System analysis 3 Algebra 2 Algebra, Boolean 2 Axiom of choice 2 Borel sets 2 Categories (Mathematics) 2 Circuits 2 Combinatorial group theory 2 Commutative algebra 2 Comparative method 2 Computable functions 2