Combining Texts

All the ideas for 'works', 'Non-Monotonic Logic' and 'First-order Logic, 2nd-order, Completeness'

expand these ideas     |    start again     |     specify just one area for these texts


21 ideas

2. Reason / E. Argument / 1. Argument
You can 'rebut' an argument's conclusion, or 'undercut' its premises [Antonelli]
4. Formal Logic / E. Nonclassical Logics / 1. Nonclassical Logics
We infer that other objects are like some exceptional object, if they share some of its properties [Antonelli]
4. Formal Logic / E. Nonclassical Logics / 12. Non-Monotonic Logic
Reasoning may be defeated by new premises, or by finding out more about the given ones [Antonelli]
Should we accept Floating Conclusions, derived from two arguments in conflict? [Antonelli]
Weakest Link Principle: prefer the argument whose weakest link is the stronger [Antonelli]
Non-monotonic core: Reflexivity, Cut, Cautious Monotonicity, Left Logical Equivalence, Right Weakening [Antonelli]
We can rank a formula by the level of surprise if it were to hold [Antonelli]
People don't actually use classical logic, but may actually use non-monotonic logic [Antonelli]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
There are at least seven possible systems of semantics for second-order logic [Rossberg]
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In proof-theory, logical form is shown by the logical constants [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
5. Theory of Logic / K. Features of Logics / 10. Monotonicity
In classical logic the relation |= has Monotony built into its definition [Antonelli]
Cautious Monotony ignores proved additions; Rational Monotony fails if the addition's negation is proved [Antonelli]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]