The first sentence of [temp.deduct.conv]/1 is supposed to be read as:
Template argument deduction is done by comparing the return type <...> with the return type <...> as described in [temp.deduct.type].
P1787R6 changed this sentence to what's in the working draft today:
Template argument deduction is done by comparing the return type of the conversion function template (call it P) with the type specified by the conversion-type-id of the conversion-function-id being looked up (call it A) as described in [temp.deduct.type].
Unfortunately, now it's much easier to read it as "being looked up as described in [temp.deduct.type]", because "by comparing" is so much farther away.