Represents several arguments in a row, spliced into the pattern that contains
PatternSequence[p1, p2, …]
MatchQ[f[1, 2, 3], f[PatternSequence[1, 2], 3]]
→ Truef[1, 2] /. f[x : PatternSequence[_, _]] -> {x}
→ {1, 2}{MatchQ[f[1, 2, 3, 4], f[PatternSequence[_, _] ..]], MatchQ[f[1, 2, 3], f[PatternSequence[_, _] ..]]}
→ {True, False}