Line 3,692: |
Line 3,692: |
| # <math>\operatorname{Sub}(x, (y, \underline{~~}))</math> puts any specified <math>x\!</math> into the empty slot of the rheme <math>(y, \underline{~~}),</math> with the effect of producing the saturated rheme <math>(y, x)\!</math> that evaluates to <math>y \cdot x.</math> | | # <math>\operatorname{Sub}(x, (y, \underline{~~}))</math> puts any specified <math>x\!</math> into the empty slot of the rheme <math>(y, \underline{~~}),</math> with the effect of producing the saturated rheme <math>(y, x)\!</math> that evaluates to <math>y \cdot x.</math> |
| | | |
− | In (1) we consider the effects of each <math>x\!</math> in its practical bearing on contexts of the form <math>(\underline{~~}, y),</math> as <math>y\!</math> ranges over <math>G,\!</math> and the effects are such that <math>x\!</math> takes <math>(\underline{~~}, y)</math> into <math>x \cdot y,</math> for <math>y\!</math> in <math>G,\!</math> all of which is summarily notated as <math>x = \{ (y : x \cdot y) : y \in G \}.</math> The pairs <math>(y : x \cdot y)</math> can be found by picking an <math>x\!</math> from the left margin of the group operation table and considering its effects on each <math>y\!</math> in turn as these run along the right margin. This produces the ''regular ante-representation'' of <math>S_3,\!</math> like so: | + | In (1) we consider the effects of each <math>x\!</math> in its practical bearing on contexts of the form <math>(\underline{~~}, y),</math> as <math>y\!</math> ranges over <math>G,\!</math> and the effects are such that <math>x\!</math> takes <math>(\underline{~~}, y)</math> into <math>x \cdot y,</math> for <math>y\!</math> in <math>G,\!</math> all of which is notated as <math>x = \{ (y : x \cdot y) ~|~ y \in G \}.</math> The pairs <math>(y : x \cdot y)</math> can be found by picking an <math>x\!</math> from the left margin of the group operation table and considering its effects on each <math>y\!</math> in turn as these run along the right margin. This produces the ''regular ante-representation'' of <math>S_3,\!</math> like so: |
| | | |
| {| align="center" cellpadding="6" width="90%" | | {| align="center" cellpadding="6" width="90%" |
Line 3,747: |
Line 3,747: |
| |} | | |} |
| | | |
− | <pre>
| + | In (2) we consider the effects of each <math>x\!</math> in its practical bearing on contexts of the form <math>(y, \underline{~~}),</math> as <math>y\!</math> ranges over <math>G,\!</math> and the effects are such that <math>x\!</math> takes <math>(y, \underline{~~})</math> into <math>y \cdot x,</math> for <math>y\!</math> in <math>G,\!</math> all of which is notated as <math>x = \{ (y : y \cdot x) ~|~ y \in G \}.</math> The pairs <math>(y : y \cdot x)</math> can be found by picking an <math>x\!</math> on the right margin of the group operation table and considering its effects on each <math>y\!</math> in turn as these run along the left margin. This generates the ''regular post-representation'' of <math>S_3,\!</math> like so: |
− | In (2), we consider the effects of each x in its | |
− | practical bearing on contexts of the form <y, _>, | |
− | as y ranges over G, and the effects are such that | |
− | x takes <y, _> into y·x, for y in G, all of which | |
− | is summarily notated as x = {(y : y·x) : y in G}. | |
− | The pairs (y : y·x) can be found by picking an x | |
− | on the right margin of the group operation table | |
− | and considering its effects on each y in turn as | |
− | these run along the left margin. This generates | |
− | the regular post-representation of S_3, like so: | |
| | | |
− | e = e:e + f:f + g:g + h:h + i:i + j:j | + | {| align="center" cellpadding="6" width="90%" |
− | | + | | |
− | f = e:f + f:g + g:e + h:i + i:j + j:h | + | <math>\begin{array}{*{13}{c}} |
− | | + | \operatorname{e} |
− | g = e:g + f:e + g:f + h:j + i:h + j:i | + | & = & \operatorname{e}:\operatorname{e} |
− | | + | & + & \operatorname{f}:\operatorname{f} |
− | h = e:h + f:j + g:i + h:e + i:g + j:f | + | & + & \operatorname{g}:\operatorname{g} |
− | | + | & + & \operatorname{h}:\operatorname{h} |
− | i = e:i + f:h + g:j + h:f + i:e + j:g | + | & + & \operatorname{i}:\operatorname{i} |
− | | + | & + & \operatorname{j}:\operatorname{j} |
− | j = e:j + f:i + g:h + h:g + i:f + j:e | + | \\[4pt] |
| + | \operatorname{f} |
| + | & = & \operatorname{e}:\operatorname{f} |
| + | & + & \operatorname{f}:\operatorname{g} |
| + | & + & \operatorname{g}:\operatorname{e} |
| + | & + & \operatorname{h}:\operatorname{i} |
| + | & + & \operatorname{i}:\operatorname{j} |
| + | & + & \operatorname{j}:\operatorname{h} |
| + | \\[4pt] |
| + | \operatorname{g} |
| + | & = & \operatorname{e}:\operatorname{g} |
| + | & + & \operatorname{f}:\operatorname{e} |
| + | & + & \operatorname{g}:\operatorname{f} |
| + | & + & \operatorname{h}:\operatorname{j} |
| + | & + & \operatorname{i}:\operatorname{h} |
| + | & + & \operatorname{j}:\operatorname{i} |
| + | \\[4pt] |
| + | \operatorname{h} |
| + | & = & \operatorname{e}:\operatorname{h} |
| + | & + & \operatorname{f}:\operatorname{j} |
| + | & + & \operatorname{g}:\operatorname{i} |
| + | & + & \operatorname{h}:\operatorname{e} |
| + | & + & \operatorname{i}:\operatorname{g} |
| + | & + & \operatorname{j}:\operatorname{f} |
| + | \\[4pt] |
| + | \operatorname{i} |
| + | & = & \operatorname{e}:\operatorname{i} |
| + | & + & \operatorname{f}:\operatorname{h} |
| + | & + & \operatorname{g}:\operatorname{j} |
| + | & + & \operatorname{h}:\operatorname{f} |
| + | & + & \operatorname{i}:\operatorname{e} |
| + | & + & \operatorname{j}:\operatorname{g} |
| + | \\[4pt] |
| + | \operatorname{j} |
| + | & = & \operatorname{e}:\operatorname{j} |
| + | & + & \operatorname{f}:\operatorname{i} |
| + | & + & \operatorname{g}:\operatorname{h} |
| + | & + & \operatorname{h}:\operatorname{g} |
| + | & + & \operatorname{i}:\operatorname{f} |
| + | & + & \operatorname{j}:\operatorname{e} |
| + | \end{array}</math> |
| + | |} |
| | | |
− | If the ante-rep looks different from the post-rep, | + | If the ante-rep looks different from the post-rep, it is just as it should be, as <math>S_3\!</math> is non-abelian (non-commutative), and so the two representations differ in the details of their practical effects, though, of course, being representations of the same abstract group, they must be isomorphic. |
− | it is just as it should be, as S_3 is non-abelian | |
− | (non-commutative), and so the two representations | |
− | differ in the details of their practical effects, | |
− | though, of course, being representations of the | |
− | same abstract group, they must be isomorphic. | |
− | </pre>
| |
| | | |
| ==Note 22== | | ==Note 22== |