Standard Options

??=[Arrow] The orientation of the central Arrow may be reversed, turned into an equality, or omitted altogether. In each case a label may still be specified, so in effect the Arrow may be replaced by anything at all.

These effects are specified by the first token in the central label, which thus has the form: |<#947#>|;SPMlt;tok;SPMgt;<#267#>label<#267#>|<#947#>| where ;SPMlt;tok;SPMgt; may be one of ...


#defs1268#

When none of these occurs then the default of |_| is assumed. If the label itself starts with one of these characters then specify |_| explicitly, or enclose the label within a group |<#273#>...<#273#>|. See 168 <#274#>Extra Options~1<#274#>, for more values of ;SPMlt;tok;SPMgt;.

2 OPTIONS for the central Arrow:


#defs275#

the position of the Arrow is determined by ``nudging'' (see below) e.g. |<#278#>^;SPMlt;num;SPMgt;label<#278#>|, where the actual dimen is |;SPMlt;num;SPMgt;@|

2
#code279#

#math452#

#tex2html_wrap_indisplay1742#

2