Does the deduction theorem fail for modal logic?
نویسندگان
چکیده
منابع مشابه
Does the deduction theorem fail for modal logic?
Various sources in the literature claim that the deduction theorem does not hold for normal modal or epistemic logic, whereas others present versions of the deduction theorem for several normal modal systems. It is shown here that the apparent problem arises from an objectionable notion of derivability from assumptions in an axiomatic system. When a traditional Hilbert-type system of axiomatic ...
متن کاملAbstract Algebraic Logic and the Deduction Theorem
ALGEBRAIC LOGIC AND THE DEDUCTION THEOREM W. J. BLOK AND D. PIGOZZI
متن کاملThe Deduction Theorem for Quantum Logic - Some Negative Results
We prove that no logic (i.e.consequence operation) determined by any class of orthomodular lattices admits the deduction theorem (Theorem 2.7). We extend those results to some broader class of logics determined by ortholattices (Corollary 2.6).
متن کاملHerbrand’s Theorem for a Modal Logic
ion X → X ′ 〈λx.X〉(t)→ 〈λx.X ′〉(t) +Lambda ¬X → ¬X ′ ¬〈λx.X〉(t)→ ¬〈λx.X ′〉(t) −Lambda Quantification For new variables x1, . . . , xn, ¬φ(x)→ ¬φ1(x) . . . ¬φ(x)→ ¬φn(x) ¬(∀x)φ(x)→ ¬[φ1(x1) ∧ . . . ∧ φn(xn)] −Quant Binding For x not free in X, X → X ′ X → 〈λx.X ′〉(t) +Bind ¬X → ¬X ′ ¬X → ¬〈λx.X ′〉(t) −Bind Definition 5.2 We say Y is a modal Herbrand expansion of X provided there is a formula X∗ ...
متن کاملA Lindstrom theorem for modal logic
A modal analogue of Lindstrr om's characterization of rst-order logic is proved. Basic modal logics are characterized as the only modal logics that have a notion of nite rank, or, equivalently, as the strongest modal logic whose formulas are preserved under ultra-products over !. Also, basic modal logic is the strongest classical logic whose formulas are preserved under bisimulations and ultra-...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Synthese
سال: 2011
ISSN: 0039-7857,1573-0964
DOI: 10.1007/s11229-011-9905-9