Peano and Grice on 'the': the inverted iota operator

Speranza

	read as ‘the’; is the inverted iota or description operator and is used in expressions for definite descriptions, such as (x)φx (which is read: the x such that φx).
[(x)φx]	a definite description in brackets; this is a scope indicator for definite descriptions.
E!	is defined at *14·02, in the context E!(x)φx, to mean that the description (x)φx is proper, i.e., there is exactly one φ.