Mathematico-logical heuristics involve using structured mathematical or logical methods to solve problems. They include techniques like calculus for optimizing functions, linear programming for maximizing or minimizing linear objectives under constraints, and 3-SAT for solving complex logical puzzles. These heuristics apply rigorous mathematical rules and logic to break down and solve problems step-by-step. They are especially useful for structured problems where precise, logical solutions are needed, like in operations research, computer science, and engineering.