22.1.2.34 eqArr
This element specifies the Array object (sometimes referred to as “Equation Array”, despite its ability to hold mathematical text other than equations), an object consisting of one or more equations, expressions, or other mathematical text runs that can be vertically justified as a unit with respect to surrounding text on the line. Alignment of multiple points within each run of mathematical text can occur within the array through the use of align values and spacer values. An align value is an ampersand within the array which acts as an alignment point (as described in 22.1.2.3). A spacer value is an ampersand (represented by “&” in the example below) within the array which designates where space can be added in order to align the align values on different rows of the array. Within each argument in the array, every odd ampersand is an align value and every even
ampersand is a spacer value (as well, the beginning of each argument provides an implied spacer value). If eqArrPr is omitted then the default values for its properties will be used. These defaults are:
Property
Default Value
“center”
“0”
“0”
“0”
[Example:
“0”
<m:eqArr>
<m:e>
<m:r>
<m:t>a=b+c</m:t>
</m:r>
</m:e>
<m:e>
<m:r>
<m:t>d+e=f</m:t>
</m:r>
</m:e>
</m:eqArr>A more complex array with alignment points, e.g.:
is represented as follows:
<m:eqArr>
<m:e>
<m:r>
<m:t>&x+&&y+&&z&&= &&10</m:t>
</m:r>
</m:e>
<m:e>
<m:r>
<m:t>3&x+&&y+&2&z&&= &&34</m:t>
</m:r>
</m:e>
<m:e>
<m:r>
<m:t>-5&x+&2&y-&&z&&= &&-
14</m:t>
</m:r>
</m:e>
</m:eqArr>Notice that the variables, operators, and digits of the sums line up properly, as the align values line up between each argument by adding space at the position of each spacer value.
end example]
[Note: The W3C XML Schema definition of this element’s content model (CT_EqArr) is located in A.6.1. end note]