I am just testing how far the built in blogger editor can help in laying out proofs. Please ignore this.
Question: prove distributivity of OR over OR ( I am using "OR" and "AND" for disjunction and conjunction operators , == for equivalence. The reasoning for each step is to the side after a --),
(The calculus used is EQ from "A logical Approach to Discrete Math". This is theorem 3.41, just something chosen at random - but I've used only axioms + theorems proven till that point in the book ) .
prove p OR (q OR r) == (p OR q) OR (p OR r)
p OR (q OR r) -- LHS
== ((p OR q) OR r) -- associativity of Or
== (( p OR q) OR r) OR false -- False is the identity of OR
== (( p OR q) OR r) OR (NOT true) -- definition of false
== (m or r) OR (NOT true) -- substituting m for (p OR q), Leibniz
== m OR (r OR (NOT true)) -- associativity of OR
== m OR ( r OR (NOT (p == p)) ) -- true is identity of ==
== m OR ( r OR ( NOT p == p )) -- distributivity of NOT over ==
== m OR (r OR (NOT p) == r OR p ) -- distributivity of OR over ==
== m OR (r OR p == r OR (NOT p)) -- symmetry of OR
== (m OR r OR p) == (m OR r OR (NOT p)) -- distributivity of OR over ==
==(p OR q OR r OR p)== (m OR r OR (NOT p)) -- replacing m with (p OR q), Leibniz
==(p OR q) OR (r OR p)== (m OR r OR (NOT p)) --associativity of OR
==(p OR q) OR (p OR r)== (m OR r OR (NOT p)) --symmetry of OR
==(p OR q) OR (p OR r)== (m OR (NOT p) OR r) --symmetry of OR
==(p OR q) OR (p OR r)== (p OR q OR (NOT p) OR r) --expanding m to p OR q, Leibniz
==(p OR q) OR (p OR r)== (p OR (NOT p) OR q OR r) --symmetry of OR
==(p OR q) OR (p OR r)== ( true OR q OR r) -- Excluded Middle
== (p OR q) OR (p OR r)== ( true OR r) -- true is the Zero of OR
== (p OR q) OR (p OR r) == true -- true is the Zero of OR
== (p OR q) OR (p OR r) -- true is the Identity of ==
== RHS . QED
Conclusion: What a mess. I need Latex dammit. Anyone know of a *non* wordpress blog with a latex plugin? (I don't want JS rendering, for which there are a few options. I want an image (png, gif, jpeg whatever) generated on the server and plugged in appropriately).
Ravi Mohan's Tech Blog. To read my non technical blog, click here
Monday, February 15, 2010
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