1A statement of judgment that identifies the issues in controversy; a statement that can be affirmed or denied. It may function as a premise or conclusion in a syllogism and can be expressed in any kind of grammatical construction (interrogative, optative, or exclamatory).
proposition
2Pertains to events that have happened, are happening, or will happen. It aims to establish truthfulness/falsity and answers the question: "Is this assertion true?"
proposition of fact
3Affirms why something has happened, is happening, or will happen. Deals with complex cause-and-effect relationships not subject to direct verification.
proposition of explanation
4Asserts that some individual, institution, program, or policy possesses or lacks a certain desirable or undesirable characteristic.
proposition of value
5Also called normative statements (the most complex type involving all preceding types). Asserts that a new program or policy should be instituted.
proposition of policy
6Must have conflicts of opinion or interest; can be believed, disbelieved, doubted, or denied.
debatability
7Should be expressed in an affirmative statement.
affirmative statement
8Should contain only one judgment (avoiding distinct separate proposals or prejudiced terms like "immoral").
single judgement
9Terms shouldn't be too vague or ambiguous; they must be understandable so both sides readily agree on their meaning.
clear terms