a proposition is a declarative statement that may be either true or false but never both.
to prove that a property exists for every statement, we prove that
- the property exists for every boolean variable
- if the property exists for statement then it also exists for
- if the property exists for the statements and then it also exists for
to represent a statement using a binary tree
- if the statement is a boolean variable, draw a single node for
examples of sentences that are (or make) true statements:
- "Socrates is a man."
- "a triangle has three sides."
- "madrid is the capital of Spain."