Completeness of deduction from premises Theorem If a is consequence of a set 2 of premises, then there is a tableau deduction of a from∑,ie.,∑a→∑卜aCompleteness of deduction from premises Theorem If α is consequence of a set Σ of premises, then there is a tableau deduction of α from Σ, i.e., Σ  α ⇒ Σ ` α. Yi Li (Fudan University) Discrete Mathematics April 24, 2012 10 / 25