Interpret a simple varstruct as a variable, even if there is a constant of that
name.
DESCRIPTION
As well as conventional abstractions `\x. t` where x is a variable, HOL
Light permits generalized abstractions where the varstruct is a more complex
term, e.g. `\(x,y). x + y`. This includes the degenerate case of just a
constant. However, one may want a regular abstraction whose bound variable
happens to be in use as a constant. When parsing a quotation "\c. t" where
c is the name of a constant, HOL Light interprets it as a simple abstraction
with a variable c when the flag ignore_constant_varstruct is true, as it
is by default. It will interpret it as a degenerate generalized abstraction,
only useful when applied to the constant c, if the flag is false.