Theorem
orl
≪
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index
|
src
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≫
theorem orl (a b: wff): $ a -> a \/ b $;
Step
Hyp
Ref
Expression
1
absurdr
a -> ~a -> b
2
1
conv
or
a -> a \/ b
Axiom use
axs_prop_calc
(
ax_1
,
ax_2
,
ax_3
,
ax_mp
)