Symbol _ Thing = Thing -- assignment to an indexed variable

Synopsis

• Operator: _

• Usage:

  x_a = v

• Inputs:
  • x, a symbol
  • a, a thing
  • v, a thing
• Outputs:
  • v
• Consequences:

  • the indexed variable x_a is assigned the value v.

Description

i1 : x_a

o1 = x
      a

o1 : IndexedVariable

i2 : x_a = b

o2 = b

o2 : Symbol

i3 : x_a

o3 = b

o3 : Symbol

i4 : x_c

o4 = x
      c

o4 : IndexedVariable

i5 : x_c = d

o5 = d

o5 : Symbol

i6 : x_c

o6 = d

o6 : Symbol

    -- code for method: Symbol _ Thing
    ../../../../../../../Macaulay2/m2/variables.m2:50:25-50:56: --source code:
    Symbol _ Thing := (X,i) -> new IndexedVariable from {X,i}
    ---------------------------------
    -- code for method: Symbol _ Thing = Thing
    ../../../../../../../Macaulay2/m2/variables.m2:58:26-61:13: --source code:
    Symbol _ Thing = (x,i,e) -> (
         x' := value x;
         if not instance(x',IndexedVariableTable) then x' = new IndexedVariableTable from x;
         x'_i = e)

i7 : peek x

o7 = IndexedVariableTable{a => b      }
                          c => d
                          symbol$ => x

See also

• IndexedVariable -- the class of all indexed variables