MyWikiBiz, Author Your Legacy — Friday October 24, 2025
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, 15:30, 23 January 2008
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| | The briefest expression for logical truth is the empty word, usually denoted by ε or λ in formal languages, where it forms the identity element for concatenation. To make it visible in this text, I denote it by the equivalent expression "(())", or, especially if operating in an algebraic context, by a simple "1". Also when working in an algebraic mode, I use the plus sign "+" for exclusive disjunction. Thus, we may express the following paraphrases of algebraic forms: | | The briefest expression for logical truth is the empty word, usually denoted by ε or λ in formal languages, where it forms the identity element for concatenation. To make it visible in this text, I denote it by the equivalent expression "(())", or, especially if operating in an algebraic context, by a simple "1". Also when working in an algebraic mode, I use the plus sign "+" for exclusive disjunction. Thus, we may express the following paraphrases of algebraic forms: |
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| − | :{| | + | :{| cellpadding="4" |
| − | | ''A'' + ''B'' || = || (''A'', ''B'') | + | | ''A'' + ''B'' |
| | + | | = |
| | + | | (''A'', ''B'') |
| | |- | | |- |
| − | | ''A'' + ''B'' + ''C'' || = || ((''A'', ''B''), ''C'') || = || (''A'', (''B'', ''C'')) | + | | ''A'' + ''B'' + ''C'' |
| | + | | = |
| | + | | ((''A'', ''B''), ''C'') |
| | + | | = |
| | + | | (''A'', (''B'', ''C'')) |
| | |} | | |} |
| | | | |
| − | One should be careful to observe that these last two expressions are not equivalent to the form (''A'', ''B'', ''C''). | + | One should be careful to observe that these last two expressions are not equivalent to the form (''A'', ''B'', ''C''). |
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| | <font face="courier new"> | | <font face="courier new"> |