γ
1
≡
γ
2
⇔
{
γ
1
(
0
)
=
γ
2
(
0
)
=
p
,
and
d
d
t
ϕ
∘
γ
1
(
t
)
∣
t
=
0
=
d
d
t
ϕ
∘
γ
2
(
t
)
∣
t
=
0