以上(いじょう) ①More than (or equal to), Over・(and) above, Any more・Greater, Exceeding

In Japanese, 以上 is used when describing a quantity or level that is more than or equal to a certain amount, focusing on everything from that point upward. On the other hand, いか is used when expressing a quantity or level that is less than or equal to a certain amount, focusing on everything from that point downward. The key nuance here is that 以上 includes the stated value while いか does not include the stated amount but rather everything up to just below that amount.

以上 and より are both used to express "more than" or "over," but they are used in different contexts. 以上 includes the stated amount or degree, meaning "more than or equal to," and often used after stating a specific amount or condition. On the other hand, より strictly means "more than" and is often used in comparisons to indicate a higher amount or degree without including the stated amount.

The primary difference between 以上 and 以上に lies in the degree of emphasis and comparison between two entities or things being compared. While 以上 is used to indicate a quantity or level that is equal to or more than a certain amount, 以上に is used to further emphasize or amplify the comparison. It suggests a sense of exceeding or surpassing the referred baseline or standard by a considerable margin. In essence, 以上に implies 'even more than' rather than just 'more than or equal to'.

While both からある and 以上 ① can be used to express "at least" or "more than," there are nuanced differences in their usage. からある is typically used when emphasizing the largeness of a number or quantity, often with somewhat of a surprised tone, akin to "as many as" or "as much as". On the other hand, 以上 ① is generally used more objectively, with no specific emotional connotation, similar to "more than" or "at least". The latter is often used in more formal contexts or to set limits or standards.