[Cyan]<Tioga>TableTool>Tableau.Mesa!1

-- Tableau.mesa

-- Last Edited by: Gnelson, November 10, 1983 2:45 pm

-- Last Edited by: Beach, January 12, 1984 1:35 pm

Tableau: DEFINITIONS = {

VariableRec: TYPE = RECORD [r: REF, i: INT, j: INT, restricted: BOOL];

-- r is for the client: Tableau does not use it.

-- i is the index of the row owned by this variable, or -1 if it doesn't own a row

-- j is the index of the column owned by this variable, or -1 if it doesn't own a column

-- the unit variable, 1 if it is the unit variable, and the negative of the unit

-- entry in its row if it owns a row.

nrows: INT = 10;

ncols: INT = 10;

x: REF ARRAY [1 .. ncols] OF Variable;

y: REF ARRAY [1 .. nrows] OF Variable;

-- (A j: j in [1, m]: x(j).j = j)

-- (A i: i in [1, n]: y(i).i = i)

NewVariable: PROC RETURNS [Variable];

Init: PROC; -- client should throw away all Variables upon calling Init.

Pivot: PROC[rowvar, colvar: Variable];

matrix: REF ARRAY[1 .. nrows] OF ARRAY[1 .. ncols] OF REAL;

-- client may want to traverse the rows or columns of the tableau, so the

-- underlying matrix is visible

n, m: INT; -- n = current number of rows; m = current number of columns.

unit: Variable;

-- the variable that is implicitly constrained equal to 1.

dcol: INT; -- in [0, m]; the largest index of a dead column.

satisfiable: BOOL;

-- Init sets this to TRUE. The Assert procedures may set it to FALSE.

-- It is an error to call and Assert procedure when it is FALSE.

-- The Assert procedures call PropEQ when they

-- detect an equality between two variables.

LinearMonomial: TYPE = RECORD [coef: REAL, var: Variable];

LinearForm: TYPE = LIST OF LinearMonomial;

AssertZ: PROC[l: LinearForm, PropEQ: PROC[u, v: Variable]];

AssertZ2: PROC[c1, c2: REAL, v1, v2: Variable, PropEQ: PROC[u, v: Variable]];

-- constrains the Tableau so that c1*v1 + c2*v2 = 0.

AssertZ3: PROC[c1, c2, c3: REAL, v1, v2, v3: Variable, PropEQ: PROC[u, v: Variable]];

-- constrains the tableau so that c1*v1 + c2*v2 + c3*v3 = 0.

Restrict: PROC[v:Variable, PropEQ: PROC[u, v: Variable]];

-- constrains the tableau so that v ge 0.

Maximize: PROC[v:Variable] RETURNS [unbounded: BOOLEAN];

-- arranges the Tableau so that the solution maximizes v.

Solution: PROC[v:Variable] RETURNS [REAL];

-- arranges the Tableau so that the solution minimizes v.