3. Excursions

The syntax for the |..twocell| types and for || is a little different to what might be expected from that for ||, ||, etc. For example,

|[|;SPMlt;hop;SPMgt;|]<#478#>|;SPMlt;displace;SPMgt;|<#478#>...|

connects to the ;SPMlt;pos;SPMgt; displaced by ;SPMlt;displace;SPMgt; from the relative cell location specified by ;SPMlt;hop;SPMgt;. The displacement can be any string of valid -pic commands, but they must be enclosed within a group |<#479#>...<#479#>|. When the cell location is required, a~null grouping |<#480#><#480#>| <#481#>must<#481#> be given.

When used with the |;SPMlt;;SPMgt;| nudge, such excursions allow a labelled Arrow to be placed anywhere within an -pic diagram; furthermore the Arrow can be oriented to point in any direction.

2 ( @#1<#997#><#997#> @#1<#998#><#998#> @#1<#999#><#999#> @@ <#486#><#486#> @@ <#487#><#487#> )

The empty object gives the default of closely spaced tiny dots, resulting in a ``smooth'' curve.

2 The following macro is used in conjunction with compiling diagrams, to include the global parameters in the compiled file.

( @<#1109#>219 @<#488#>twocell objects<#488#><#1000#>220 <#489#>@ <#489#>221 <#490#>@ <#490#>222 <#491#>@ <#491#>223 <#492#>@ <#492#>224 <#493#>@ <#493#>225 <#494#>Arrowobject@<#494#>226 <#1000#><#1109#> )