spielwiese
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Last change
on this file since 1ebec3 was
891438c,
checked in by Gerhard Pfister <pfister@…>, 23 years ago
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*GP: initial release
git-svn-id: file:///usr/local/Singular/svn/trunk@5579 2c84dea3-7e68-4137-9b89-c4e89433aadc
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-
Property mode set to
100644
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File size:
774 bytes
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| 1 | LIB "tst.lib"; |
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| 2 | tst_init(); |
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| 3 | |
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| 4 | LIB"algebra.lib"; |
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| 5 | proc isCohenMacaulay(ideal I) |
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| 6 | { |
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| 7 | def A = basering; |
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| 8 | list L = noetherNormal(I); |
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| 9 | map phi = A,L[1]; |
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| 10 | I = phi(I); |
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| 11 | int s = nvars(basering)-size(L[2]); |
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| 12 | execute("ring B=("+charstr(A)+"),x(1..s),ds;"); |
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| 13 | ideal m = maxideal(1); |
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| 14 | map psi = A,m; |
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| 15 | ideal J = std(psi(I)); |
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| 16 | ideal K = kbase(J); |
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| 17 | setring A; |
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| 18 | execute("ring C=("+charstr(A)+"),("+varstr(A)+"),(dp(s),ds);"); |
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| 19 | ideal I = imap(A,I); |
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| 20 | qring D = std(I); |
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| 21 | ideal K = fetch(B,K); |
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| 22 | module N = std(syz(K)); |
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| 23 | intvec v = leadexp(N[size(N)]); |
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| 24 | int i=1; |
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| 25 | while((i<s)&&(v[i]==0)){i++;} |
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| 26 | if(!v[i]){return(0);} |
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| 27 | return(1); |
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| 28 | } |
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| 29 | |
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| 30 | ring r=0,(x,y,z),ds; |
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| 31 | ideal I=xz,yz; |
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| 32 | isCohenMacaulay(I); |
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| 33 | |
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| 34 | I=x2-y3; |
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| 35 | isCohenMacaulay(I); |
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| 36 | |
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| 37 | tst_status(1);$ |
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