This permits the reintroduction of the rule of Uniform Substitution.
Hence, Lewis's rule of Uniform Substitution fails (if p∧¬p is substituted for p in ◊p we derive ◊(p∧¬p), which is L-false, not L-true).
We conclude that in many cases the simple first-best rule of uniform emission pricing remains a practical guideline for unilateral climate policy design.
The system, following Frege, is based on implication $C $$ and negation $N $$ alone, with the elegant axiom set and three rules of inference: modus ponens, a rule of uniform substitution of formulas for propositional variables, and a rule of definitional replacement.
For a taste of what they can do, notice that they yield a succinct justification of a rule of Uniform Substitution, whereby a formula of the form $A(B/p)$ is a theorem whenever $A$ is a theorem, provided that $B$ is free for $p$ in $A$.
There is a position - not at all unfamiliar in contemporary discussion - which says that to be a citizen is essentially and simply to be under the rule of the uniform law of a sovereign state, in such a way that any other relations, commitments or protocols of behaviour belong exclusively to the realm of the private and of individual choice.
The transformation rules of T are uniform substitution, modus ponens, and a rule to the effect that if α is a theorem so is Lα (the rule of necessitation).
NASD officials said that the new rule would also help make compliance practices and enforcement of rules uniform at securities firms.
It also has power over all matters deemed in need of uniform rules across the country.
They called for the establishment of uniform rules for gymnasts, coaches and spotters.
