<!-- tex4ht_begin tex_complex_tex4ht_math math 1 --> (I − D)φ(t) <!-- tex4ht_end tex_complex_tex4ht_math math 1 --> <!-- tex4ht_begin tex_complex_tex4ht_math math 2 --> ϕwV t <!-- tex4ht_end tex_complex_tex4ht_math math 2 --> <!-- tex4ht_begin tex_complex_tex4ht_math math 3 --> h ˙ψϕ <!-- tex4ht_end tex_complex_tex4ht_math math 3 -->