...36 <#2340#>1<#2340#><#2340#>1<#2340#>
<#476#>Actually, that's a little white lie --- trying to persuade TEX to do run-time type checking isn't much fun. So the TEX implementation of this is actually a <#205#>refinement<#205#> where the Error condition has been replaced by whatever it is TEX does if you try doing <#206#>\ifnum x ;SPMlt; y<#206#> when x and y aren't numbers<#476#>