Describing Things

The picture to the right will be used in this exercise. The picture contains a variety of things. Despite its simplicity there are many things that could be written down to describe aspects of the picture. First , write down, in English, one or more informal descriptions of the world depicted in this picture. Next, using the syntax of propositional logic, write down a set of propositions, both simple and complex, that describe aspects of the world depicted in this picture. Next to each proposition write down an English sentence that corresponds to that proposition. Finally, using the syntax of first order logic, write down a set of expressions, both simple and complex, that describe aspects of the world depicted in this picture. Next to each expression write down an English sentence that corresponds to that expression.
Some Questions:
What were some things that were : (1) impossible, or (2) very hard, or (3) awkard to express in English; in the propositional logic; in the first order logic. Compare the terms used in the informal English description and the terms used in the English sentences that corresponded to the logical expressions. What are some of the differences? Is it possible to write down all of the expressions that are true in the world depicted in this picture?

	Deduction
© Charles F. Schmidt