( 1)? p→q，(2)？ (sVt)，(3)？ (qA？ 7r)V(-q？ ^r),(4)？ (r？ As)V(→rA？ -s)，(5)？ 1-? +(p？ Q) Meet all requirements.
Therefore, the conjunctions of (1) ~ (5) are required to be true. Suppose: A≈(p→q)? A(SV 1)Ba((Q Ba→R)V(→QλR))A((Ras)V(R Ba-S))∩(T →( P Q))？
In order to find out each scheduling scheme, we should find out the disjunctive normal form of A, preferably the principal disjunctive normal form. The number of minimal items contained in the principal disjunctive normal form is the number of scheduling schemes, and how to assign values is given by the true assignment of each minimal item. Therefore, the principal disjunctive paradigm of A is needed.
The main steps to find the principal disjunctive normal form of A are as follows:
A branch, the real assignment is 00 1 10 and 1 100 1.
Scheme 1: Sun and Li will go abroad, but Zhao, Qian and Zhou will not go abroad.
Option 2: Zhao, Qian and Zhou go abroad, but Sun and Li don't.
With the advent of the information age, the mainstream position of continuous mathematics represented by calculus has changed in the era of industrial revolution, and the importance of discrete mathematics has been gradually recognized by people. The ideas and methods taught in discrete mathematics are widely reflected in various fields of computer science and technology and related majors, from scientific calculation to information processing, from theoretical computer science to computer application technology, from computer software to computer hardware, from artificial intelligence to cognitive system, which are closely related to discrete mathematics.
Because the digital electronic computer is a discrete structure, it can only deal with discrete or discrete quantitative relations. Therefore, both computer science itself and modern scientific research fields closely related to computer science and its application are faced with the problem of how to establish corresponding mathematical models for discrete structures. How to discretize the mathematical model established by continuous quantitative relationship so that it can be processed by computer.
Discrete mathematics is a comprehensive subject which integrates traditional logic, set theory (including function), number theory, algorithm design, combinatorial analysis, discrete probability, relation theory, graph theory and tree, abstract algebra (including algebraic system, group, ring, field, etc.). ), Boolean algebra, computational models (languages and automata) and so on. The application of discrete mathematics covers many fields of modern science and technology.
Discrete mathematics can also be said to be the basic core discipline of computer science. There is a famous typical example in discrete mathematics-the four-color theorem, also known as the four-color conjecture, which is one of the three major mathematical problems in the modern world. It was put forward by the British draftsman Fernandez guthrie in 1852. When he colored the map, he found a phenomenon, "Each map can only be colored in four colors, and *.
So can this be proved mathematically? 100 years later 1976, Kenneth Appel and Wolfgang Haken used computer-aided calculation, which took 1200 hours and 1000 billion judgments, and finally proved the four-color theorem, causing a sensation in the world. This is discrete mathematics.
References:
Baidu encyclopedia-discrete mathematics