In classical mechanics,
particularly Lagrangian Mechanics, a holonomic constraint is a special type of constraint of motion. It restricts the trajectory of a system of particles to a smooth manifold Q by the set smooth equations
a({x},t)=0
b({x},t)=0
.
.
.
Where
t=time
{x}= the set of 3N Cartesian coordinates for the system of N particles.
For N particles, the number of holonomic constraints must be less than 3N using the
assumption that each equation has an explicit
dependence to AT LEAST one coordinate.
A rigid body,
defined by the constraint equations (
using LaTeX) is
\left| {x_i - x_j } \right| - c_{ij} = 0
where i is not
equal to j is a Holonomic Constraint.