43     public function equals(object $other) : bool  argument
45         if ($this === $other) {
49         return $other instanceof self
50             && $this->start === $other->start
51             && $this->stop === $other->stop;
57     public function startsBeforeDisjoint(Interval $other) : bool  argument
59         return $this->start < $other->start && $this->stop < $other->start;
65     public function startsBeforeNonDisjoint(Interval $other) : bool  argument
67         return $this->start <= $other->start && $this->stop >= $other->start;
73     public function startsAfter(Interval $other) : bool  argument
75         return $this->start > $other->start;
81     public function startsAfterDisjoint(Interval $other) : bool  argument
83         return $this->start > $other->stop;
89     public function startsAfterNonDisjoint(Interval $other) : bool  argument
92         return $this->start > $other->start && $this->start <= $other->stop;
98     public function disjoint(Interval $other) : bool  argument
100         return $this->startsBeforeDisjoint($other) || $this->startsAfterDisjoint($other);
106     public function adjacent(Interval $other) : bool  argument
108         return $this->start === $other->stop + 1 || $this->stop === $other->start - 1;
114     public function union(Interval $other) : self  argument
116         return new self(\min($this->start, $other->start), \max($this->stop, $other->stop));
122     public function intersection(Interval $other) : self  argument
124         return new self(\max($this->start, $other->start), \min($this->stop, $other->stop));