Description: A virtual deduction elimination rule. (Contributed by Alan Sare, 24-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
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Hypotheses | e210.1 | |- (. ph ,. ps ->. ch ). |
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e210.2 | |- (. ph ->. th ). |
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e210.3 | |- ta |
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e210.4 | |- ( ch -> ( th -> ( ta -> et ) ) ) |
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Assertion | e210 | |- (. ph ,. ps ->. et ). |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | e210.1 | |- (. ph ,. ps ->. ch ). |
|
2 | e210.2 | |- (. ph ->. th ). |
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3 | e210.3 | |- ta |
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4 | e210.4 | |- ( ch -> ( th -> ( ta -> et ) ) ) |
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5 | 3 | vd01 | |- (. ph ->. ta ). |
6 | 1 2 5 4 | e211 | |- (. ph ,. ps ->. et ). |