The phrase "a first assumption is" is correct and usable in written English.
It can be used when introducing an initial hypothesis or belief that will be discussed or analyzed further.
Example: "A first assumption is that all participants have a basic understanding of the subject matter before the workshop begins."
Alternatives: "an initial assumption is" or "a preliminary assumption is".
A second assumption is that the financial sector will accept the new arrangements in perpetuity.
A fourth assumption is that human nature is intensely social.
A second assumption is that all effects that match the global signal are of no interest and can be removed.
A second assumption is about the light properties, which is supposed to be perfectly diffused, since the sun is far enough to be considered as an illumination source situated at infinite distance.
However, notice that conditions (PM1 - PM4) only refer to the interval ([ 0,infty ) ). In the field of fixed point theory, a fifth assumption is usually considered. (PM5): (lim_{trightarrowinfty}F_{xy}(t)=1) for all (x,yin X). (lim_{trightarrowinfty}F_{xy}(t)=1) for all (x,yin X). A discussion about the necessity of this condition can be found in [19].
However, notice that conditions (PM1 - PM4) only refer to the interval ([ 0,infty ) ). (2) In the field of fixed point theory, a fifth assumption is usually considered. (PM5): (lim_{trightarrowinfty}F_{xy}(t)=1) for all (x,yin X). A discussion about the necessity of this condition can be found in [19].
A second assumption is that single sets of selected areas are adequate indicators of incidental representation or the species accumulation index.
A second assumption is that clustering applied to the expression data will identify co-regulated groups of genes, or, alternately, that it captures important trends in the data that may arise from multiple influences.
A second assumption is that a link exists between P4P indicators and true improvements in quality.
