Hypergendered Logic Source
Hypergendered Logic — Page 14
𝑃𝐴¬ 𝑥∧¬𝑦 ( ) ( ) ≡𝑃𝐴¬𝑥∨𝑦 ( ). 10. Outer-PA De Morgan Now consider the user’s explicit outer example: ¬𝑃𝐴𝑥 ( ) ∧¬𝑃𝐴¬𝑦 ( ). By De Morgan at the outer state level, ¬𝑃𝐴𝑥 ( ) ∧¬𝑃𝐴¬𝑦 ( ) ≡¬ 𝑃𝐴𝑥 ( ) ∨𝑃𝐴¬𝑦 ( ) ( ). Likewise, ¬𝑃𝐴𝑥 ( ) ∨¬𝑃𝐴¬𝑦 ( ) ≡¬ 𝑃𝐴𝑥 ( ) ∧𝑃𝐴¬𝑦 ( ) ( ). Notice what De Morgan does not license: ¬𝑃𝐴𝑥 ( )≢𝑃𝐴¬𝑥 ( ). The outer negation stays outside unless HGL explicitly applies an antithetical operator that changes the content of the PA-state. 11. Mixed-depth example Suppose 𝑆= 𝑃𝐴𝑥∧¬𝑦 ( ) ∧𝑃𝐴¬𝑦 ( ). Then ¬𝑆≡¬𝑃𝐴𝑥∧¬𝑦 ( ) ∨¬𝑃𝐴¬𝑦 ( ). If we also inspect the inner content of the first PA term, we may separately note ¬ 𝑥∧¬𝑦 ( ) ≡¬𝑥∨𝑦. But we may not jump from ¬𝑃𝐴𝑥∧¬𝑦 ( ) to 𝑃𝐴¬𝑥∨𝑦 ( ) by De Morgan alone. That would move the negation through the PA operator, which is a different operation. This is one of the most important discipline rules in the whole field: De Morgan may rewrite what a negation scopes over. It does not give permission to move a negation across a non-Boolean operator. 12. Eight worked De Morgan examples Example 1: inner conjunction 𝑃𝐴¬ 𝑥∧𝑦 ( ) ( ) ≡𝑃𝐴¬𝑥∨¬𝑦 ( ). Example 2: inner disjunction 𝑃𝐴¬ 𝑥∨𝑦 ( ) ( ) ≡𝑃𝐴¬𝑥∧¬𝑦 ( ). Example 3: outer conjunction of states ¬ 𝑃𝐴𝑥 ( ) ∧𝑃𝐴𝑦 ( ) ( ) ≡¬𝑃𝐴𝑥 ( ) ∨¬𝑃𝐴𝑦 ( ).
Source Canon: Verbatim mathematical and modal logic. Interactive navigation and operator lookups available at /#hgl-part:14.