In mathematics, the Poincaré duality theorem, named after Henri Poincaré, is a basic result on the structure of the homology and cohomology groups of manifolds. It states that the kth Cohomogy group of an n-dimensional oriented closed manifold is isomorphic to the (n-k)th Homology group of M, for all integers k
This six-panel trucker cap with a mesh back will be a comfy and classic choice for a perfect day in the sun.
• 60% cotton, 40% polyester
• Mid-profile cap with a low-profile embroidery area
• Structured, six-panel cap
• 3.5″ crown (8.9 cm)
• Hard buckram front panels
• Mesh back
• Permacurv® visor, matching undervisor
• Plastic adjustable closure
• Head circumference: 21⅝″–23⅝″ (54.9 cm–60 cm)
This six-panel trucker cap with a mesh back will be a comfy and classic choice for a perfect day in the sun.
• 60% cotton, 40% polyester
• Mid-profile cap with a low-profile embroidery area
• Structured, six-panel cap
• 3.5″ crown (8.9 cm)
• Hard buckram front panels
• Mesh back
• Permacurv® visor, matching undervisor
• Plastic adjustable closure
• Head circumference: 21⅝″–23⅝″ (54.9 cm–60 cm)