Declaring math versions

<#312#>decl<#312#> | | <#313#>version-name<#313#> Defines <#315#>version-name<#315#> to be a math version. The newly declared version is initialised with the defaults for all symbol fonts and math alphabets declared so far (see the commands | | and | |). If used on an already existing version, an information message is written to the transcript file and all previous | | or | | declarations for this version are overwritten by the math alphabet and symbol font defaults, i.e.~one ends up with a virgin math version. Example: <#316#>tex2html_preform<#316#>verbatim48#