envIsVal

envIsVal(
t_tool[.Partition]
t_varName
[ g_faultIn ]
)
=> t / nil

Indicates whether a particular variable has been loaded and whether it exists for the given tool[.partition].

t_tool[.Partition]	The name of the tool and the partition, if any. A partition is a way of grouping related sets of variables associated with a tool.
t_varName	The name of the variable.
g_faultIn	Determines whether to fault in the tool if the variable is not loaded. Faulting in is the process of reading the `.cdsenv` file and initializing the variables.

`t`	The variable is currently loaded. If not, the faultIn flag determines whether to fault in that tool and then the query for the existence of the specified variable takes place.
`nil`	The variable is not loaded.