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# At each decoding stage, the Fano algorithm retains the information regarding three paths: the current path, its immediate predecessor path, and one of its successor paths.
# Based on this information, the Fano algorithm can move from the current path to either its immediate predecessor path or the selected successor path; hence, no stack is required for queuing all examined paths.
# The movement of the Fano algorithm is guided by a dynamic threshold {{var|T}} that is an integer multiple of a fixed step size ¢.
# Only the path whose path metric is no less than {{var|T}} can be next visited. According to the algorithm, the process of codeword search continues to move forward along a code path, as long as the Fano metric along the code path remains non-decreasing.
# Once all the successor path metrics are smaller than {{var|T}}, the algorithm moves backward to the predecessor path if the predecessor path metric beats {{var|T}}; thereafter, threshold examination will be subsequently performed on another successor path of this revisited predecessor.
# In case the predecessor path metric is also less than {{var|T}}, the threshold {{var|T}} is one-step lowered so that the algorithm is not trapped on the current path.
# For the Fano algorithm, if a path is revisited, the presently examined dynamic threshold is always lower than the momentary dynamic threshold at the previous visit, guaranteeing that looping in the algorithm does not occur, and that the algorithm can ultimately reach a terminal node of the code tree, and stop.
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