For reactions involving oxygen, the gain of oxygen implies the oxidation of the atom or molecule to which the oxygen is added (and the oxygen is reduced). In organic compounds, such as butane or ethanol, the loss of hydrogen implies oxidation of the molecule from which it is lost (and the hydrogen is reduced).
In Ethiopian Orthodoxy, fasting (tsome) lasts for 55 continuous days before Easter (Fasika), although the fast is divided into three separate periods: Tsome Hirkal, eight days commemorating an early Christian figure; Tsome Arba, forty days of Lent; and Tsome Himamat, seven days commemorating Holy Week.
Therefore, when the Church expanded the period of fasting and prayer in preparation for Easter from a few days to 40 days (to mirror Christâs fasting in the desert, before He began His public ministry), Sundays could not be included in the count.