Can we move quantifiers to the left in predicate logic?
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31-10-2019 - |
Pergunta
Say I have part of a query in the form: ∃xa(...)∧∃xb(...)∧∃xc(...), where a, b, and c are attributes and the ellipses can be anything (I'm looking for a general rule). Is this equivalent to saying ∃xa,xb,xc(...∧...∧...) - i.e. compacting all the existential quantifiers into one and 'anding' their domains together?
For example, if I have the query:
would it be correct (albeit unwieldy) to write it as:
{ xpid | ∃xpname,xcolor,xsid,xsname,xaddress,xcost,ysid,ysname,yaddress,ycost( PARTS(xpid,xpname,xcolor) ∧ SUPPLIERS(xsid,xsname,xaddress... (and then the rest of the query)
Nenhuma solução correta
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