I know the basics about the difference in the usage between は and が. Nevertheless, when it comes to more complex sentences, I encounter difficulties that I want to explain on base of some examples. Maybe, somebody can briefly confirm whether my understanding is correct.
Looking at the X-ray image, it is apparent that the package of the component described above cracked.
I think it is clear that "前述の部品" is the topic and can or should be marked with "は".
It is no doubt that the package of the component described above cracked.
Although the constructions of both sentences are very similar, "疑いようがありません" must be preceded by "ことは" and "前述の部品" cannot be the topic and hence becomes a genitive.
Assuming that the temperature of the device described above excessively increased, the failure picture can be explained.
I am sure that "前述の部品" cannot be marked with "は" but can anybody explain me why? Can the part of the sentence preceding "仮定" be regarded as relative clause where "は" is not permitted at all?
Is this sentence correct?
It is reasonable to think that the improvement measure described above guarantees protection for the components.
"前述の改選策" cannot be marked with "は" because this could run counter to the "と考えることは".
I highly appreciate your collaboration. This "は" versus "が" topic is my main concern.