8. In a computer system, a method for formatting a plurality of mathematical expressions that occupy one or more lines in a document, comprising: aligning the plurality of mathematical expressions, comprising: initializing and utilizing an expression editing tool to format the plurality of mathematical expressions, the expression editing tool: identifying an anchor point for a first mathematical expression; identifying an alignment point for each line of each mathematical expression; determining a horizontal indent for a first line of a second mathematical expression such that the alignment point of the second mathematical expression and the anchor point of the first mathematical expression have the same horizontal position; inserting the horizontal indent into the first line with the expression editing tool; wherein, during alignment, each line has limitless horizontal space; after the alignment, determining if a portion of the second mathematical expression on the first line crosses a second margin of the document; if the portion of the second mathematical expression crosses the second margin on the first line, forcing an automatic break for the portion of the second mathematical expression crossing the second margin and calculating a total indention to maintain a meaning of the second mathematical expression: determining the amount of an automatic break indention for the portion of the second mathematical expression crossing the second margin, wherein the automatic break indention is the distance on a next line to align a first element of the portion of the second mathematical expression crossing the second margin with a first element on the first line after the alignment point of the second mathematical expression, determining the amount of the alignment indention, and adding with the expression editing tool the amount of the automatic break indention and the alignment indention to calculate the total indention; moving with the expression editing tool the portion of the second mathematical expression that crosses the second margin to the next line of the document; and applying with the expression editing tool the total indention to the moved portion.
8. In a computer system, a method for formatting a plurality of mathematical expressions that occupy one or more lines in a document, comprising: aligning the plurality of mathematical expressions, comprising: initializing and utilizing an expression editing tool to format the plurality of mathematical expressions, the expression editing tool: identifying an anchor point for a first mathematical expression; identifying an alignment point for each line of each mathematical expression; determining a horizontal indent for a first line of a second mathematical expression such that the alignment point of the second mathematical expression and the anchor point of the first mathematical expression have the same horizontal position; inserting the horizontal indent into the first line with the expression editing tool; wherein, during alignment, each line has limitless horizontal space; after the alignment, determining if a portion of the second mathematical expression on the first line crosses a second margin of the document; if the portion of the second mathematical expression crosses the second margin on the first line, forcing an automatic break for the portion of the second mathematical expression crossing the second margin and calculating a total indention to maintain a meaning of the second mathematical expression: determining the amount of an automatic break indention for the portion of the second mathematical expression crossing the second margin, wherein the automatic break indention is the distance on a next line to align a first element of the portion of the second mathematical expression crossing the second margin with a first element on the first line after the alignment point of the second mathematical expression, determining the amount of the alignment indention, and adding with the expression editing tool the amount of the automatic break indention and the alignment indention to calculate the total indention; moving with the expression editing tool the portion of the second mathematical expression that crosses the second margin to the next line of the document; and applying with the expression editing tool the total indention to the moved portion. 15. A method as defined in claim 8 , wherein the anchor point of the first mathematical expression is automatically selected by scanning and comparing each mathematical expression in the plurality of mathematical expressions to find one or more elements common to all mathematical expressions.