The following expression returns <s>Now</s>.
<substr> <s>Now is the time</s> <i>0</i> <i>3</i> </substr>
In the following example, the start attribute is missing, but is assumed to be 0:
<block> <substr l=’4’> <s>Hello World</s> --> Hello World </substr> --> Hell </block> --> Hell
The length argument is also optional. A missing length argument causes the function to extract the rest of the string. length can be unspecified when only the string and start arguments are specified a child nodes of substr such as:
<substr> <s>Hello World</s> <i>3</i> <substr>
or when the l attribute is missing from the substr node like. Note that the length argument is unspecified below, but the rest of the string starting from this start is returned:
<block> <substr s=’3’> <s>Hello World</s> --> Hello World </substr> --> lo World </block> --> lo World