PREDICATE LOGIC.(25 pts)
A. Let P(x) be the statement x 2 > x4. If the domain consists of the integers,
what are the truth values?
1. P(0)
2. P(-1)
3. P(1)
4. P(2)
5. ∃xP(x)
6. ∀xP(x)
B. Write the following predicates symbolically and determine its truth value.
Note: Use at least three (3) values for the variables. (5 pts each)
1. for every real number x, if x>1 then x – 1 > 1
2. for some real number x, x2 ≤ 0
C. Translate the following English sentence into symbol. (3 pts each)
1. No one in this class is wearing pants and a guitarist.
Let:
Domain of x is all persons
A(x): x is wearing pants
B(x): x is a guitarist
C(x): belongs to the class
2. No one in this class is wearing pants and a guitarist.
Let:
Domain of x is persons in this class
A(x): x is wearing pants
B(x): x is a guitarist
3. There is a student at your school who knows C++ but who doesn’t
know Java.
Let:
Domain: all students at your school
C(x): x knows C++
J(x): x knows Java
(A) To answer these questions, we first solve the indicated inequality for all real numbers .
Conclusion,
Moving on to the answers to these questions :
1.
2.
3.
4.
5.
6.
(B) Let be the statement and is . Then, the sentence " for every real number x, if then " has the form
For example,
Let be the statement . Then, the sentence " for some real number , " has the form
For example,
(C)
1.No one in this class is wearing pants and a guitarist.
Let:
Domain of is all persons
is wearing pants
is a guitarist
belongs to the class
2. No one in this class is wearing pants and a guitarist.
Let:
Domain of is persons in this class
is wearing pants
is a guitarist
3. There is a student at your school who knows C++ but who doesn’t
know Java.
Let:
Domain: all students at your school
knows C++
knows Java
Q.E.D.
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