[expr.sub]/1 defines subscripting through pointer arithmetic

The expression E1[E2] is identical (by definition) to *((E1)+(E2))

[expr.add]/4, defining pointer arithmetic, uses syntax looking like subscripting

… if P points to element x[i] of an array object x with n elements,81 the expressions P + J and J + P (where J has the value j) point to the (possibly-hypothetical) element x[i+j]…

Not that x[i] necessarily means subscripting expression, but I think it is still better to replace such constructs with plain English wording like

i-th element of an array object x

instead of

element x[i] of an array object x