ABSTRACT
Consider, in the plane, the problem of integrating a function f of a complex variable around a closed curve C, e.g., the unit circle. We have, for example, ∫ c z d z = 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429502408/295d3acc-dfa3-4421-a2d3-a9c22ffb681c/content/eq1.tif"/> ∫ c d z z ≠ 0 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429502408/295d3acc-dfa3-4421-a2d3-a9c22ffb681c/content/eq2.tif"/>
