1, using P rule and R as general premise (just like S); But it should be stated: additional premise.

2. When C is deduced, the final conclusion can be directly written as: R → C; The explanation of this step is: CP rule.

Discrete mathematics is a mathematical discipline that studies the structure and relationship of discrete quantities and an important branch of modern mathematics. The meaning of discreteness refers to different connecting elements. The structure based on discreteness and the relationship between them are mainly studied, and its objects are generally finite or countable elements.

Extended data:

Subject content:

1. set theory: sets and their operations, binary relations and functions, natural numbers and natural number set, cardinality of sets.

2. Graph theory: the basic concept of graph, Euler graph and hamiltonian graph, tree, matrix representation of graph, graph, graph coloring, dominance set, covering set, independent set and matching, weighted graph and its application.

3. Algebraic structure: the basic concepts of algebraic system, semigroup and singularity, group, ring and field, lattice and Boolean algebra.

4. Combinatorial mathematics: combinatorial existence theorem, basic counting formula, combinatorial counting method and combinatorial counting theorem.

5. Mathematical logic: propositional logic, first-order predicate calculus and solving principle.