  We analyse the nature of the confinement of an infinitely long (and finite)
linear semiflexible homo-polymer chain confined in between two geometrical
constraints (A&B) under good solvent condition in two dimensions. The
constraints are stair shaped impenetrable lines. A lattice model of fully
directed self avoiding walk is used to list information of walks of the
confined chain and the exact enumeration technique is used for the canonical
ensemble of conformations of the confined chain to discuss equilibrium
statistics of the chain. We obtain the probability of polymerization of the
confined flexible chain segments with either one end (polymer trains) or both
the ends of the confined chain lying on the stair shaped constraints (polymer
bridge and arc). We have also calculated the force of confinement exerted by
the constraints on to the chain or the force exerted by the chain on the
geometrical constraints using grand canonical ensemble theory and discuss
nature of variation of the force.
