For the following proof by contradiction provide the justifications at each step, using the following equivalences and inference rules. Use the following keys:
aIdempotent Law
bDouble Negation
cDe Morgan's Law
dCommutative Properties
eAssociative Properties
fDistributive Properties
gEquivalence of Contrapositive
hDefinition of Implication
iDefinition of Equivalence
jIdentity Laws
kTautology
lContradiction
mNegation of the goal to prove
nModus Ponens
oModus Tollens
pTransitivity of Implication
qConjunctive Simplification
rConjunctive Addition
sDisjunctive Addition

We want to prove by a proof by contradiction from the following propositions.

by

by between and

by between and previously deduced.

by from

We have and true, therefore we have a contradiction.

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