linear hyperbolic equation of higer order高阶线性双曲（型）方程
- weakly isomorphic automorphism
- weakly locally contractible
- weakly lower semicontinuity
- weakly lower semicontinuous
- weakly measurable function
- weakly mixing automorphism
- weakly mixing condition
- weakly mixing transformation
- weakly modular lattice
- weakly n-dimensional space
- weakly nilpotent group
- weakly nonlinear
- weakly nonlinear equation
- weakly nonlinear system
- weakly nonwandering set
- weakly normal family
- weakly normal subgroup
- weakly o-minimal structure
- weakly o-minimal theory
- weakly ordered field
- weakly orthogonal subspace
- weakly polar kernel
- weakly positive quadratic form
- weakly precompact set
- weakly primary ideal