(p→q)→(q→r)

(p→q)∨(q→r) becomes conjunctive disjunction.

(? p∨q)∨(？ Q∨r) becomes conjunctive disjunction.

(p∧？ q)∨(？ De Morgan's law

(p∧？ q)∨？ Q∞r associative law

Q∨r conjunctive disjunctive absorption rate

(? p∧p)∨？ Q∨r complement

(? p∨？ q∨r)∧(p∨？ Q∨r) distribution law 2

Get the master conjunctive normal form, and then check the missing largest item.

m？ ∧M∏(2，6)

∏(0, 1,3,4,5,7)? ∑(0, 1,3,4,5,7)? m？ ∨m？ ∨m？ ∨m？ ∨m？ ∨m？

(p∨q∨r)∨？ (p∨q∨？ r)∨？ (p∨？ q∨？ r)∨？ (? p∨q∨r)∨？ (? p∨q∨？ r)∨？ (? p∨？ q∨？ De Morgan's law

(? p∧？ q∧？ r)∩(？ p∧？ q∧r)∨(？ p∧q∧r)∨(p∧？ q∧？ r)∩(p∧？ Q∧r)∨(p∧q∧r) De Morgan's Law

Get the principal disjunctive normal form

2

P(A)={？ ,{ 1},{2},{ 1,2}}

P(A)×A={(？ , 1),({ 1}, 1}), ({2}, 1), ({ 1,2}, 1), (? ,2),({ 1},2}), ({2},2), ({ 1,2},2)}

three

R = { & ltb，a & gt，& ltb，c & gt，& ltc，a & gt，& ltc，d & gt，& ltd，b & gt}

Reflexive closure r (r) =

1 0 0 0

1 1 1 0

1 0 1 1

0 1 0 1

Symmetric closure s (r) =

0 1 1 0

1 0 1 1

1 1 0 1

0 1 1 0

Transitive closure t (r) =

0 0 0 0

1 1 1 1

1 1 0 1

1 1 1 1

four

Hastu

Turn left | turn right

Set b = {4,6}

The largest element is 4,6.

The smallest element is 4, 6.

Infinite certainty

There is a lower bound of 2.